af·fin·i·ty 
(ə-fĭnĭ-tē)
(ə-fĭnĭ-tē)n. pl. af·fin·i·ties
1.
a. A natural attraction, liking, or feeling of kinship: a special affinity with animals; a cultural affinity for the automobile.
b. A natural tendency or ability to use or do something: an affinity with languages; an affinity for making money.
c. A natural compatibility of one thing with another: “the affinity of pork and shellfish” (Alison Arnett).
2. Relationship by marriage: related by affinity to the wife.
3.
a. An inherent similarity between persons or things: “The genius of the Afro-Cubans lay in recognizing the affinity between swing-era jazz and their own tradition” (Gene Santoro).
b. Biology A relationship or resemblance in structure between species that suggests a common origin.
4.
a. An attraction or force between particles or chemicals that causes them to combine.
b. The degree to which particles or chemicals are likely to combine: Hemoglobin has a high affinity for oxygen. Also called avidity.
[Middle English affinite, relationship by marriage, from Old French afinite, from Latin affīnitās, from affīnis, related by marriage; see AFFINED.]
Usage Note: In the sense of “attraction,” affinity may be followed by of, between, or with. Thus one may speak of the close affinity of James and Samuel, or of the affinity between James and Samuel, or of James's affinity with Samuel. In its chemical use affinity is generally followed by for: a dye with an affinity for synthetic fabrics. · One might want to avoid using affinity as a simple synonym for liking, since almost half of the Usage Panel in 2016 rejected the example Her affinity for living in California led her to reject a chance to return to New York. Nevertheless, the sophisticated tone of affinity can lend an archness to certain contexts, as when Barbara Tuchman writes of Kaiser Wilhelm's “affinity for coarse physical jokes practiced upon his courtiers.” This may be why 79 percent of the Usage Panel approved of this quotation when it was presented as an example.