Likeness, similarity, resemblance, similitude, analogy, affinity are comparable when they denote agreement or correspondence or an instance of agreement or correspondence in details (as of appearance, structure, or qualities) brought out by a comparison of two or more things.
Likeness commonly implies closer correspondence than similarity, which often applies to things which are merely somewhat alike.
Resemblance suggests especially similarity in appearance or in superficial or external qualities.
Similitude, which is somewhat infrequent and bookish, is occasionally preferred to likeness or similarity when an abstract term is desired.
Analogy distinctively implies comparison of things which are unlike, not only specifically or generically, but often even in substance or essence, and it more often draws attention to likeness or parallelism in relations rather than in appearances or qualities. Philosophically, it suggests such assumptions as that similar causes will produce similar effects or that what is true in one order of existence must be true in another.
Affinity adds to resemblance the implications of such a relationship as natural kinship, temperamental sympathy, similar experience, or historical influence, which is responsible for the likeness.