bunghole vs arse

bunghole and arse both are nouns.

Word	Noun	Adjective	Verb	Adverb
bunghole	Yes	No	No	No
arse	Yes	No	No	No

As nouns, bunghole and arse are synonyms defined as:

Other synonyms of bunghole include arsehole, asshole.

bunghole (noun)	arse (noun)
a hole in a barrel or cask; used to fill or empty it	vulgar slang for anus
vulgar slang for anus	the fleshy part of the human body that you sit on