Bottom commonly refers to the human buttocks, but also has other uses
The buttocks (anatomical nates, clunium, gluteus, regio glutealis) are rounded portions of the anatomy located on the posterior of the pelvic region of the apes, humans and many other bipeds or quadrupeds.
The buttocks are formed by the masses of the gluteal muscles or 'glutes' (the gluteus maximus and the gluteus medius) superimposed by a layer of fat. The superior aspect of the buttock ends at the iliac crest, and the lower aspect is outlined by the horizontal gluteal crease. The gluteus maximus has two insertion points: 1/3 superior portion of the linea aspera of the femur (leg bone), and the superior portion of the iliotibial tractus. The masses of the gluteus maximus muscle are separated by an intermediate gluteal cleft or "crack" in which the anus is situated.
The buttocks allow primates to sit upright without needing to rest their weight on their feet as four-legged animals do.
Some baboons and all gibbons, though otherwise fur-covered, have characteristic naked callosities on their buttocks. While women and boys generally have smooth so-called 'baby-bottoms', adult men have varying degrees of hairgrowth, as on other parts of their body.
Most consider well-formed buttocks to be sexually attractive. However, the definition of "well-formed" is not fixed, as sexual aesthetics of the buttocks vary considerably from culture to culture, from one period of fashion to another and even from person to person.
In ancient astrology], various parts of the body were associated with signs of the zodiac - e.g. the buttocks to the Libra, the Balance. Depending on the context, exposure of the buttocks in non-intimate situations often causes feelings of shame, embarrassment or humiliation in a non-exhibitionist subject, and embarrassment or amusement in a non-voyeurist audience. Expressions such as being "caught with your pants down" or more explicitly in Dutch, "met de billen bloot" ("with bared buttocks"), use the image as a metaphor for non-physical embarrassment as well.
Willfully exposing one's own bare buttocks as a protest, a provocation, or for fun is called "mooning".
A "wedgie" is pulling someone's undergarments or swimming trunks up through their buttock "crack" to be hauled over the top of the victim's trousers, sometimes partially baring the victim's buttocks.
It is no coincidence that the English verb to spank is the only one specifically meant for physical discipline of a specific part of the body, and various other languages have terms specifically referring to spanking; in many punitive traditions, the buttocks are the preferential target for painful lessons, from educational to judicial, as offering them for punishment (especially divested) adds a psychological dose of embarrassment and even sexual humiliation to the pain, which can be meted out with less risk of long-term corporal harm than elsewhere. Thus in various cultural traditions, expressions like "A black man's ears are in his buttocks" (e.g. in Uganda) or "seat of learning" clearly refer to the preferential paining of the posterior in a submissively bent and exposed position.
Many comedians, writers and others rely on the buttocks in these and other ways (such as flatulence and toilet humor) as a source of amusement, camaraderie and fun, despite (or in some cases for the sake of) the risk of being in dubious taste, if not censored.
Because in most cultures the buttocks are rarely shown naked, they are generally considered unsuitable for ornamental body markings and body modification, but may be preferential for discreet markings, such as secretive membership proof or to be shown in intimate company (e.g. amongst lovers).
Quite commonly phrases use the buttocks as a pars pro toto for a whole person, but generally with a negative connotation. For example, terminating an employee may be described as "firing his ass". One might say "move your ass" or "haul ass" (or the polite, understood euphemisms "move it" or "haul it") as an exhortation to greater haste or urgency. Expressed as a function of punishment, defeat or assault becomes "kicking one's ass". Such phrases also may suggest a person's characteristics, e.g. difficult people are termed "hard asses" (polite euphemism: "hard nosed"). People deemed excessively puritanical or frugal may be termed "tight asses" (polite euphemism: "tightwads"). An annoying person or any source of frustration may be termed "a pain in the ass".
The anatomical Latin name for the buttocks is nates, but is rarely used. As buttocks are an object of both shame and fascination, it is not surprising that there are many colloquial terms, euphemistic, ironic or other, to refer to them. These include the following:
- backside, posterior, behind and its derivates (hind-quarters, hinder or the childish heinie), rear or rear-end, derrière (French for "behind") - all strictly positional descriptions, as the inaccurate use of rump (as in 'rump roast', after a 'hot' spanking), thighs, upper legs; analogous are
- aft, stern and poop, naval in origin
- caboose, originally a ship's galley in wooden cabin on deck; also the "rear end" car of a freight train considered a cute synonym suitable for any audience
- bottom (and the shortening "bot" as well as childish diminutives "bottie" or "botty"), booty (black slang for the female ody since the 1920s) as famously by K.C. and the Sunshine Band's Shake Your Booty, is an 'artistic liberty'
- tail (strictly anatomically a zoomorphism, humans only have a tail-bone; also used for the even more sensual phallus) and tail-end
- tush or tushy (from the Yiddish / Hebrew "tuchis" or "tochis" meaning "under" or "beneath")
- trunk, in American English, particularly when describing large buttocks "junk in the trunk". This usage refers metaphorically to an automobile's trunk.
- arse or ass, and (butt-)hole - a pars pro toto (strictly only the actual anal region); also used as an insult for a person
- badonkadonk - onomatopoeic slang meaning the voluptuously bouncing, large yet firm buttocks of a woman
- breech, a metaphorical sense derived from on older form of the garment breeches (as the French culotte meaning pantoloons, via cul from Latin culus 'butt'), so 'bare breech' means without breeches, i.e. trouserless butt
- bum - in British English, used frequently in the United Kingdom, Canada, Australia and many other English speaking Commonwealth Countries, is a mild often humorous reference to buttocks, not necessarily in vulgar or sexual context; however also used in reference to anal intercourse, often as an insult, as in bum boy (for a homosexual). Also verb - to practise anal intercourse. (In U.S. the same word is used for a type of person giving a new meaning to "bums on seats")
- buns, mounds - a geographical mound, from (Old) French butte "mound, knoll") and orbs - shape-metaphors, usually in the plural
- bund - derived from Punjabi
- bundas - buttocks. Portuguese origin.
- butt - the common term for buttocks in the US, used in everyday speech. It is also acceptable in print.
- can (a container) had an unusual development: Slang meaning "toilet" is c. 1900, said to be a shortening of piss-can, meaning "buttocks" from
- cheeks, a shape-metaphor within human anatomy, but also used in the singular: left cheek and right cheek; sounds particularly naughty because of the homonym and the adjective cheeky, lending themselves to word puns
- fanny - a socially acceptable term in print, in the United States at least, for many years before some of the bolder terms came along; and a subject of jokes, since "Fannie" can be a woman's name, diminutive of "Frances". However, in British English fanny refers to the female genitals or vulva and is considered vulgar.
- fourth point of contact: in military slang, because of the sequence of textbook parachute jump landing
- fundament (literally "foundation", not common in this general sense in English, but for the butt since 1297)
- hams, like buttocks generally as a plural, after the meat cut from the analogous part of a hog; pressed ham refers to mooning against a window; brawn, a singular derived from the Frankish for ham or roast, is also used for both a muscular body part (but either on arms or legs) or boar meat, especially roast
- moneymaker, a term coming from exotic dancers and other entertainers who use their buttocks (even clothed) to earn money. It is usually used in reference to females.
- moon was a common shape-metaphor for the butt in English since 1756, and the verb to moon meant 'to expose to (moon)light' since 1601, long before they were combined in US student slang in the verb (al expression) mooning "to flash the buttocks" in 1968.
- prat (British English, origin unknown; as in pratfall, a vaudeville term; also a term of abuse for a person)
- seat (of the trousers; or metaphorically) another long-standing socially acceptable term, referring to the use for sitting - but compare the sarcastic use of seat of wisdom and similar expressions, such as 'seat of learning', referring to use as target for an 'educational' spanking.
- ultimatum (Latin, literally 'the outer-most') was used in slang c.1820s.
- The word "callipygian" is sometimes used to describe someone with notably attractive buttocks. The term comes from the Greek kallipygos, (first used for the Venus Kallipygos) which literally means "beautiful buttocks"; the prefix is also a root of "calligraphy" ("beautiful writing") and "calliope" ("beautiful voice")
- Both the English (in) tails and the Dutch billentikker ('tapping the buttocks') are ironic terms for very formal coats with a significantly longer tail end as part of festive (especially wedding party) dress
- a pygopag(ous) (from the Greek pygè 'buttock' and pagein 'attached') was a monster in Ancient (Greek) mythology consisting of two bodies joint by common buttocks, now a medical term for (Siamese) twins thus joint back-to-back
- pygophilia is sexual arousal or excitement caused by seeing, playing with or touching the woman's buttocks; people who have strong attraction to the woman's buttocks are called pygophilists.
- pygoscopia means observing someone's rear; pygoscopophobia a pathological fear to be its unwilling object
- pygalgia is soreness in the buttocks, i.e. a pain in the rump.
- Steatopygia is a marked accumulation of fat in and around the buttocks.
- uropygial in ornithology mean, situated on, belonging to, the uropygium, i.e. the rump of a bird
- "bubble butt" has at least two connotations, which are at odds with each other: either a small, round and firm pair of buttocks resembling a pair of soap bubbles next to each other, or a large rear end, seemingly about to burst from the strain. In both cases, the term implies an appealing shapeliness about the buttocks.
In most cultures with a (partial) nudity taboo, this specifically applies to the buttocks (as usually to the most erogenous zones), so mainstream garments generally cover them completely, even when that is not a practical requirement. An example of another attitude in an otherwise hardly exhibitionist culture is the Japanese fundoshi.
Clothing can be used to accentuate the buttocks. Some articles are designed specifically to show off the buttocks or to expose them, both outer or single layer garments and underwear (visible only in the bedroom or locker room). Wearing only thong underwear or a black vinyl dress with a large hole cut out of the back might be examples. Wearing thong underwear with pants is done to hide "panty lines", creases in the pant caused by certain underwear that breaks the smooth line of the body. Both of these choices are undertaken for style. However, some articles merely have utilitarian features. The butt flap in a union suit, used to allow baring only the bottom with a simple gesture (as for hygiene), is a good example. That flap was so ubiquitous that it was used in cartoons and comics for generations.
Emphasis on one part or another of the body tends to shift with generations. The 1880s were well-known for the fashion trend called the bustle, which provided even the skinniest woman with seemingly huge buttocks. Like long underwear with its flap, this clothing style was acknowledged in popular media for generations afterward. The popularity of this fashion is shown in the famous Georges Seurat painting Sunday Afternoon on the Island of La Grande Jatte in the two women to the far left and right.
Later, the cleavage of the buttocks could be exposed by some women as fashion dictated trousers be worn lower.