The butt or 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, 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 butt or buttocks allow primates to sit upright without needing to rest their weight on their feet as four-legged
animals do. Females of certain species of baboon have red buttocks that "blush" to attract males. In the case of humans,
females tend to have wider and thicker buttocks due to higher subcutaneous fat and wider hips.
Synonyms:
The anatomical Latin name for the buttocks is nates (pronounced NEY-teez in English), which is plural; the singular, natis (buttock), 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 homophone heinie, strictly the whole body behind the hind leg-trunk attachment), 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; in nautical jargon, buttocks also designates the aftermost portion of a hull above the water line and in front of the rudder, merging with the run below the water line
- 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
- Nude cyclists with painted buttocksbottom (and the shortening "bot" as well as childish diminutives "bottie" or "botty"), but the use of similar-sounding booty (slang for the female body since the 1920s) as famously by K.C. and the Sunshine Band's Shake Your Booty, is an 'artistic liberty'; equivalents in other languages include the Latino culo from Latin culus, 'bottom'
- tail (strictly anatomically a zoomorphism, humans only have a tail-bone, yet the illogical tail feather was popularized by musicians; also used for the even more sensual phallus) and tail-end
- Tush or tushy (from the Yiddish language "tuchis" or "tochis" meaning "under" or "beneath")
- Dumper sometimes denotates the buttocks, especially when talking about a large butt.
- 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, asshole, and (butt-)hole - a pars pro toto (strictly only the actual body cavity and directly adjoining anal region); also used as an insult for a person. The term is Anglo-Saxon dialect, and therefore dates back over a thousand years.
- 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, Ireland, Canada, Australia, New Zealand and many other English speaking Commonwealth countries, also historically in U.S., is a mild often humorous reference to buttocks, not necessarily in vulgar or sexual context: "I've a boil on my bum, thrice as large as my thumb" - The Judge With The Sore Rump, St. George Tucker. Also used in reference to anal intercourse, often as an insult, as in bum boy (for a homosexual). Also a verb - to practise anal intercourse.
- buns, mounds (cfr. Butte, a geographical mound, known since 1805 in American English, from (Old) French butte "mound, knoll") and orbs - shape-metaphors.
- bund - derived from Punjabi
- bunda - bottom, of Brazilian Portuguese origin.
- butt - the common term for a pair of buttocks (singular, as one body-part; cognate but neither its root nor an abbreviation) in the US, used in everyday speech. It is also acceptable in print.
- can (a container) had an unusual development: the slang meaning "toilet" is recorded circa 1900, said to be a shortening of piss-can, the meaning "buttocks" from c. 1910, verb meaning "fire an employee" (to flush=dump?) from 1905.
- 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
- culo - (From Spanish/Italian/) slang, usually meaning a woman's voluptuous, round and firm buttocks. Put simply the Latino equivalent of booty, although in Spanish it is considered vulgar and offensive (but less so in Spain than in Latin America).
- 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. The figure of a bare-bottomed lass named Fanny is ubiquitous in Provence (the southeast of France) wherever pétanque is played: traditionally when a player loses 13 to 0 it is said that “il est fanny” (he's fanny), and he has to kiss the bottom of a girl called Fanny; as there is rarely an obliging Fanny, there is always a substitute picture, woodcarving or pottery so that Fanny’s bottom is always available.[2]
- 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)
- Gand or Gaand - a Hindi derivate
- 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
- hurdies - British, origin unknown, also applied to the whole rump
- moneymaker, a term coming from exotic dancers and other entertainers who use their buttocks (even clothed) to earn money; usually referencing 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.
- 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.
- sit-upon; has various independent counterparts in other languages, e.g. Dutch zitvlak ('sitting plain'), German Gesäß (~=guh|seys), Italian sedere
