arse

Short definition from Wiktionary

Noun

1. 1
   The buttocks or more specifically, the anus.
2. 2
   A stupid, pompous, arrogant, mean or despicable person.
3. 3
   Used in similes to express something bad or unpleasant.
4. 4
   A person; the self; (reflexively) oneself or one's person, chiefly their body; (by extension) one's personal safety, or figuratively one's job, prospects, etc.
5. 5
   Abbreviation of arylsulfatase E, an enzyme, deficiencies in which are associated with abnormalities in cartilage and bone development.

Verb

1. 1
   To be silly, act stupid or mess around.

Interjection

1. 1
   An expression of frustration.