transitive verb

1. to dull the luster of or discolor the surface of (a metal) as by exposure to air
2. 1. to besmirch or sully (a reputation, honor, etc.)
   2. to spoil, mar, or debase to tarnish a memory

Etymology: < Fr terniss-, inflectional stem of ternir, to make dim < MFr, prob. < OHG tarnjan, to conceal < tarni, hidden

intransitive verb

1. to lose luster; grow dull; discolor, as from oxidation
2. to become sullied, soiled, spoiled, marred, etc.

noun

1. the condition of being tarnished; dullness
2. the film of discoloration on the surface of tarnished metal
3. a stain; blemish