1. A natural understanding and sympathy between people: "Many classical musicians have an affinity for jazz."
2. Family resemblance or a relationship by marriage.
3. An inherent similarity between people or things: "There is a close affinity between lemons and limes."

"She felt an affinity with all of those who suffered in that their pains were her pains."

4. Etymology: Affinity comes from Latin affinitas, which means "kinship by marriage, as distinct from blood kinship".

"In the 18th century, naturalists started to use affinity to mean a family resemblance (as between cats and lions)."