noun

• A natural attraction or feeling of kinship to a person or thing.
• A family relationship through marriage of a relative (e.g. sister-in-law), as opposed to consanguinity (e.g. sister).
• A kinsman or kinswoman of a such relationship; one who is affinal.
• The fact of and manner in which something is related to another.
• Any romantic relationship.
• A love interest; a paramour.
• Any passionate love for something.
• (taxonomy) Resemblances between biological populations, suggesting that they have a common origin, type or stock.
• (geology) Structural resemblances between minerals; resemblances that suggest that they are of a common origin or type.
• (chemistry) An attractive force between atoms, or groups of atoms, that contributes towards their forming bonds.
• (medicine) The attraction between an antibody and an antigen
• (computing) A tendency to keep a task running on the same processor in a symmetric multiprocessing operating system to reduce the frequency of cache misses.
• (geometry) An automorphism of affine space.