v. & n.
--v.
1. tr. lessen or destroy the lustre of (metal etc.).
2 tr. impair (one's reputation etc.).
3 intr. (of metal etc.) lose lustre.
--n.
1. a a loss of lustre. b a film of colour formed on an exposed surface of a mineral or metal.
2 a blemish; a stain.
Derivatives:
tarnishable adj.
Etymology: F ternir f. terne dark