affinity

• IPA^(key): /əˈfɪnɪti/

From Old French affinité.

affinity (countable and uncountable, plural affinities)

1. A natural attraction or feeling of kinship to a person or thing.
2. A family relationship through marriage of a relative (e.g. sister-in-law), as opposed to consanguinity (e.g. sister).
3. A kinsman or kinswoman of a such relationship; one who is affinal.
4. The fact of and manner in which something is related to another.
   • 1997, Chris Horrocks, Introducing Foucault, page 67, The Renaissance Episteme (Totem Books, Icon Books; ISBN 1840460865:

     A “signature” was placed on all things by God to indicate their affinities — but it was hidden, hence the search for arcane knowledge. Knowing was guessing and interpreting, not observing or demonstrating.

5. Any romantic relationship.
6. Any passionate love for something.
7. (taxonomy) resemblances between biological populations; resemblances that suggest that they are of a common origin, type or stock.
8. (geology) structural resemblances between minerals; resemblances that suggest that they are of a common origin or type.
9. (chemistry) An attractive force between atoms, or groups of atoms, that contributes towards their forming bonds
10. (medicine) The attraction between an antibody and an antigen
11. (computing) tendency to keep a task running on the same processor in a symmetric multiprocessing operating system to reduce the frequency of cache misses
12. (geometry) An automorphism of affine space.

• microaffinity