likeness vs ikon

likeness and ikon both are nouns.

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

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

likeness: picture consisting of a graphic image of a person or thing
ikon: a visual representation (of an object or scene or person or abstraction) produced on a surface

Other hypernyms of likeness include icon, image, picture.

likeness (noun)	ikon (noun)
picture consisting of a graphic image of a person or thing	a visual representation (of an object or scene or person or abstraction) produced on a surface
similarity in appearance or character or nature between persons or things	a conventional religious painting in oil on a small wooden panel; venerated in the Eastern Church