comparison vs likening

comparison and likening both are nouns.

Word	Noun	Adjective	Verb	Adverb
comparison	Yes	No	No	No
likening	Yes	No	No	No

As nouns, likening is a hyponym of comparison; that is, likening is a word with a more specific, narrower meaning than comparison:

Other hyponyms of comparison include analogy, collation, confrontation, contrast.

comparison (noun)	likening (noun)
the act of examining resemblances	the act of comparing similarities
qualities that are comparable
relation based on similarities and differences