Definition of: affinity

(ə·fin′ə·tē) noun plural ·ties
1. Any natural drawing or inclination; close relation or agreement.
2. Biol. A structural or physiologic likeness in different organisms indicative of a common origin.
3. Structural likenesses indicating a common origin, as in languages.
4. Chem. The force of attraction by which differing chemical elements unite to form compounds.
5. Connection through certain relations formed, as by church or state; especially, relationship through marriage (as opposed to blood relationship).
6. A Platonic or spiritual attraction held to exist between certain persons, especially between those of opposite sexes; also, the person exerting such attraction. [<L affinitas, -tatis <affinis adjacent, related < ad- to + finis end] Synonyms: alliance, analogy, birth, blood, consanguinity, descent, family, kin, kind, kindred, race, relationship.
Kind is broader than kin, denoting the most general relationship, as one of the whole human species in man kind, human kind, etc.; kin and kindred denote direct relationship that can be traced through either blood or marriage, especially the former; either of these words may signify collectively all persons of the same blood or members of the same family, relatives or relations. Affinity is relationship by marriage, consanguinity is relationship by blood. Antonyms:
See ANTIPATHY.