noun

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.

5. Any romantic relationship.

6. Any passionate love for something.

7. Resemblances between biological populations; resemblances that suggest that they are of a common origin, type or stock.

8. Structural resemblances between minerals; resemblances that suggest that they are of a common origin or type.

9. An attractive force between atoms, or groups of atoms, that contributes towards their forming bonds

10. The attraction between an antibody and an antigen

11. Tendency to keep a task running on the same processor in a symmetric multiprocessing operating system to reduce the frequency of cache misses

12. An automorphism of affine space.