/ əˈfɪnəti; NAmE / noun ( pl. -ies ) ( formal )
1.
[ sing. ] affinity (for / with sb/sth) | affinity (between A and B) a strong feeling that you understand sb/sth and like them or it
SYN rapport :
Sam was born in the country and had a deep affinity with nature.
2.
[ U , C ] affinity (with sb/sth) | affinity (between A and B) a close relationship between two people or things that have similar qualities, structures or features :
There is a close affinity between Italian and Spanish.
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WORD ORIGIN
Middle English (in the sense relationship by marriage ): via Old French from Latin affinitas , from affinis related (literally bordering on), from ad- to + finis border.