The English word of Greek origin "callipygian" indicates someone who has beautiful buttocks. However, the qualities that make buttocks beautiful or well-formed are 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.
Depending on the context, exposure of the buttocks in non-intimate situations can cause feelings of embarrassment or humiliation, and embarrassment or amusement in an onlooker (see pantsing).
Willfully exposing one's own bare buttocks as a protest, a provocation, or just for fun is called mooning.
In many punitive traditions, the buttocks are a common target for corporal punishment, which can be meted out with no risk of long-term physical harm compared with the dangers of applying it to other parts of the body, such as the hands, which could easily be damaged. The buttocks have often been described as "the place provided by nature" for this purpose.
In Western and some other cultures, many comedians, writers and others rely on the buttocks as a source of amusement, camaraderie and fun.
Students at Stanford University conduct a "mass-mooning" in May 1995
In American English, phrases use the buttocks or synonyms (especially "butt" and "ass") as a synecdoche or pars pro toto for a whole person, often 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" 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". In America an annoying person or any source of frustration may be termed "a pain in the ass" (a synonym for "a pain in the neck"). People deemed excessively puritanical or proper may be termed "tight asses" (in Australia and New Zealand, "tight arse" refers...