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.