irony vs witticism

irony and witticism both are nouns.

Word	Noun	Adjective	Verb	Adverb
irony	Yes	No	No	No
witticism	Yes	No	No	No

As nouns, witticism is a hypernym of irony; that is, witticism is a word with a broader meaning than irony:

irony: witty language used to convey insults or scorn
witticism: a message whose ingenuity or verbal skill or incongruity has the power to evoke laughter

Other hypernyms of irony include humor, humour, wit, wittiness.

irony (noun)	witticism (noun)
incongruity between what might be expected and what actually occurs	a message whose ingenuity or verbal skill or incongruity has the power to evoke laughter
a trope that involves incongruity between what is expected and what occurs
witty language used to convey insults or scorn