bunk vs Irish bull

bunk and Irish bull both are nouns.

Word	Noun	Adjective	Verb	Adverb
bunk	Yes	No	Yes	No
Irish bull	Yes	No	No	No

As nouns, Irish bull is a hyponym of bunk; that is, Irish bull is a word with a more specific, narrower meaning than bunk:

Other hyponyms of bunk include bull, bullshit, crap, dogshit, horseshit, shit.

bunk (noun)	Irish bull (noun)
a bed on a ship or train; usually in tiers	Obscene word for unacceptable behavior
a rough bed (as at a campsite)
beds built one above the other
a long trough for feeding cattle
unacceptable behavior (especially ludicrously false statements)
a message that seems to convey no meaning

bunk (verb)	Irish bull (verb)
flee; take to one's heels; cut and run
provide with a bunk
avoid paying