\Tar"nish\, v. t. [imp. & p. p. {Tarnished}; p. pr. &
vb. n. {Tarnishing}.] [F. ternir, fr. OHG. tarnen to darken,
to conceal, hide; akin to OS. dernian to hide, AS. dernan,
dyrnan, OHG. tarni hidden, OS. derni, AS. derne, dyrne. Cf.
{Dern}, a., and see {-ish}.]
To soil, or change the appearance of, especially by an
alternation induced by the air, or by dust, or the like; to
diminish, dull, or destroy the luster of; to sully; as, to
tarnish a metal; to tarnish gilding; to tarnish the purity of
color. ``Tarnished lace.'' --Fuller. Used also figuratively;
as, to tarnish one's honor.
Syn: To sully; stain; dim.

\Tar"nish\, v. i.
To lose luster; to become dull; as, gilding will tarnish in a
foul air.
      Till thy fresh glories, which now shine so bright, Grow
      stale and tarnish with our daily sight.  --Dryden.

\Tar"nish\, n.
1. The quality or state of being tarnished; stain; soil;
   blemish.
2. (Min.) A thin film on the surface of a metal, usually due
   to a slight alteration of the original color; as, the
   steel tarnish in columbite.