Common reference to the fleshy part of a human's anatomy, which one sits on.
This is the rounded fleshy part of the anatomy of apes, humans, as well as other bipeds and quadrupeds.
It is formed by the mass of muscles, known as the 'glutes'
The muscle is divided in two, with the anus in between.
13th Century middle English word BUTTUC, in which BUTT refers to a strip of land.
Modern English changed the uc' to 'ock'
It is this feature which allows for primates, to stand upright on their rear legs.
It allows for them to rest their weight on the buttocks, instead of their hind legs being needed to help distribute the body weight.
Also considered a part of the human anatomy that is sexually arousing, that elicits a natural erotic response.
Practice (Associated Acts):
Many cultures associate the bare buttocks as being unacceptable. It is associated with a person's erogenous zones, or cause of a person's sexual arousal, hence its requirement to be covered up.
Due to these cultural prohibitions, many who have their buttocks exposed, are subject to a sense of embarrassment, shame.
Those exposed to suddenly witnessing such an exposure, express shock, outrage even for such a public display of 'nudity'
The only body part, specifically targeted for punishment, such as in the case of spanking, caning, and other measures to administer punishment.
The fact that the exposure of a bare buttocks, was cause for humiliation, added to the effectiveness of such public punishment such as caning, spanking.
Female humans usually (generally) have thicker and wider buttocks than male humans, due to having wider spaced hips, and more subcutaneous fat.
Certain female baboon species have red tinted buttocks, that change hue, or blush, in order to attract the male of the species.
Within American English, the term or its synonyms have been adapted to refer to the entire person, rather than to just that body feature.
When used in this manner, it is generally considered derogatory, or negative in meaning.
Such as 'he is such a bum' had a negative meaning.
Also used to imply haste or urgency, such as the phrase 'haul your ass' or 'get your ass in gear'.
The Buttocks or its various synonyms are often used by many comedians as a source of humor.
In ancient astrology, many signs were associated with human body parts.
The buttocks was associated with 'balance' (Libra) as the shape of the two halves where identical, and provided 'balance' for humans to stand upright.
Today's Libra is represented by the lady holding scales, to impart the significance of balance.