What does affinity mean?
The definition of affinity
Af*fin”i*ty, n.; pl. Affinities(#).
Etym: [OF. afinité, F. affinité, L. affinites, fr. affinis. See Affined.]

1 Relationship by marriage (as between a husband and his wife’s blood relations, or between a wife and her husband’s blood relations); — in contradistinction to consanguinity, or relationship by blood; — followed by with, to, or between. Solomon made affinity with Pharaoh. 1 Kings iii. 1.
2 Kinship generally; close agreement; relation; conformity; resemblance; connection; as, the affinity of sounds, of colors, or of languages. There is a close affinity between imposture and credulity. Sir G. C. Lewis.
2 Companionship; acquaintance. [Obs.] About forty years past, I began a happy affinity with William Cranmer. Burton.
4 (Chem.)
That attraction which takes place, at an insensible distance, between the heterogeneous particles of bodies, and unites them to form chemical compounds; chemism; chemical or elective affinity or attraction.
5 (Nat. Hist.)
A relation between species or highe
6 (Spiritualism)
A superior spiritual relationship or attraction held to exist sometimes between persons, esp. persons of the opposite sex; also, the man or woman who exerts such psychical or spiritual attraction.