to dull the luster of (a metallic surface), especially by oxidation; discolor.
2.
to diminish or destroy the purity of; stain; sully: The scandal tarnished his reputation.
verb (used without object)
3.
to grow dull or discolored; lose luster.
4.
to become sullied.
noun
5.
a tarnished coating.
6.
tarnished condition; discoloration; alteration of the luster of a metal.
7.
a stain or blemish.
Origin: 1590–1600; < Middle Frenchterniss-, long stem of ternir to dull, deaden, derivative of terne dull, wan < Germanic; compare Old High Germantarni, cognate with Old Saxonderni,Old Englishdierne hidden, obscure; see -ish2
to lose or cause to lose the shine, esp by exposure to air or moisture resulting in surface oxidation; discolour: silver tarnishes quickly
2.
to stain or become stained; taint or spoil: a fraud that tarnished his reputation
—n
3.
a tarnished condition, surface, or film
[C16: from Old French ternir to make dull, from terne lustreless, of Germanic origin; related to Old High German tarnen to conceal, Old English dierne hidden]
1598, from prp. stem of M.Fr. ternir "dull the luster or brightness of, make dim" (15c.), probably from O.Fr. adj. terne "dull, dark," from a Frank. source cognate with O.H.G. tarnjan "to conceal, hide," O.E. dyrnan "to hide, darken," from P.Gmc. *darnijaz, related to dark.
Figurative sense is from 1697. The noun is recorded from 1713.