arse vs bunghole

arse and bunghole both are nouns.

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

As nouns, arse and bunghole are synonyms defined as:

Other synonyms of arse include arsehole, asshole.

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