affinity
(əˈfɪnɪtɪ) noun plural -ties 1 (foll by with or for) a natural liking, taste, or inclination towards a person or thing
2 the person or thing so liked
3 a close similarity in appearance or quality; inherent likeness
4 relationship by marriage or by ties other than of blood, as by adoption. Compare
consanguinity 5 similarity in structure, form, etc, between different animals, plants, or languages
6 chemistry a the tendency for two substances to combine; chemical attraction
b a measure of the tendency of a chemical reaction to take place expressed in terms of the free energy change. Symbol: A
7 biology a measure of the degree of interaction between two molecules, such as an antigen and antibody or a hormone and its receptor
[C14: via Old French from Latin affīnitāt- connected by marriage, from affīnis bordering on, related]
> afˈfinitive adjective