1. The state, quality, or fact of being like; resemblance.
2. An imitative appearance; a semblance.
3. A pictorial, graphic, or sculptured representation of something; an image.

Synonyms: These nouns denote agreement or conformity. Likeness implies close agreement: It was your uncanny likeness to my brother that made me stare at you.
Similarity and similitude suggest agreement only in some respects or to some degree: They were drawn to each other by similarity of interests. "A striking similitude between the brother and sister now first arrested my attention" (Edgar Allan Poe).
Resemblance refers to similarity in external or superficial details: "The child . . . bore a remarkable resemblance to her grandfather" (Lytton Strachey).
Analogy is similarity, as of properties or functions, between things that are otherwise not comparable: The operation of a computer presents an interesting analogy to the working of the human brain.
Affinity is likeness deriving from kinship or from the possession of shared properties or sympathies: Being an orphan, she felt an affinity with other parentless children.