likeness vs similarity

likeness and similarity both are nouns.

Word	Noun	Adjective	Verb	Adverb
likeness	Yes	No	No	No
similarity	Yes	No	No	No

As nouns, similarity is a hypernym of likeness; that is, similarity is a word with a broader meaning than likeness:

likeness: similarity in appearance or character or nature between persons or things
similarity: the quality of being similar

likeness (noun)	similarity (noun)
picture consisting of a graphic image of a person or thing	the quality of being similar
similarity in appearance or character or nature between persons or things	a Gestalt principle of organization holding that (other things being equal) parts of a stimulus field that are similar to each other tend to be perceived as belonging together as a unit