Discoloration of metal surface caused by oxidation.

Roget 848: blemish, disfigurement, deformity; adactylism^†; flaw, defect etc. (imperfection) 651; injury etc. (deterioration) 659; spots on the sun^†; eyesore.    stain, blot; spot, spottiness; speck, speckle, blur.    tarnish, smudge; dirt etc. 653.    [blemish on a person's skin: list] freckle, mole, macula [Anat.], patch, blotch, birthmark; blobber lip^†, blubber lip; blain^†, maculation; scar, wem^†; pustule; whelk; excrescence, pimple etc. (protuberance) 250.    ... show more

Roget 874: disrepute, discredit; ill repute, bad repute, bad name, bad odor, bad favor, ill name, ill odor, ill favor; disapprobation etc. 932; ingloriousness, derogation; abasement, debasement; abjectness etc. adj.; degradation, dedecoration^†; a long farewell to all my greatness [Henry VIII]; odium, obloquy, opprobrium, ignominy.    dishonor, disgrace; shame, humiliation; scandal, baseness, vileness^†; turpitude etc. (improbity) 940^†; infamy.    tarnish, taint, defilement, pollution.    stain, blot, spot, blur, stigma, brand, reproach, imputation, slur.    crying shame, burning shame; scandalum magnatum [Lat.], badge of infamy, blot in one's escutcheon; bend sinister, bar sinister; champain^†, point champain^†; byword of reproach; Ichabod.    argumentum ad verecundiam [Lat.]; sense of shame etc. 879.    ... show more

Make dirty or spotty, as by exposure to air; also used metaphorically:
— The silver was tarnished by the long exposure to the air.

synonyms: defile, maculate, stain, sully.

Roget 874: be inglorious etc. adj.; incur disgrace etc. n.; have a bad name, earn a bad name; put a halter round one's neck, wear a halter round one's neck; disgrace oneself, expose oneself.    play second fiddle; lose caste; pale one's ineffectual fire; recede into the shade; fall from one's high estate; keep in the background etc. (modesty) 881; be conscious of disgrace etc. (humility) 879; look blue, look foolish, look like a fool; cut a poor figure, cut a sorry figure; laugh on the wrong side of the mouth; make a sorry face, go away with a flea in.    one's ear, slink away.    cause shame etc. n.; shame, disgrace, put to shame, dishonor; throw dishonor upon, cast dishonor upon, fling dishonor upon, reflect dishonor upon etc. n.; be a reproach etc. n.. to; derogate from.    tarnish, stain, blot sully, taint; discredit; degrade, debase, defile; beggar; expel etc. (punish) 972.    impute shame to, brand, post, stigmatize, vilify, defame, slur, cast a slur upon, hold up to shame, send to Coventry; tread under foot, trample under foot; show up, drag through the mire, heap dirt upon; reprehend etc. 932.    bring low, put down, snub; take down a peg, take down a peg lower, take down a peg or two.    obscure.    eclipse, outshine, take the shine out of; throw into the shade, cast into the shade; overshadow; leave in the background, put in the background; push into a corner, put one's nose out of joint; put out, put out of countenance.    upset, throw off one's center; discompose, disconcert; put to the blush etc. (humble) 879.    ... show more

Roget 429: lose color etc. 428; fade, fly, go; become colorless etc. adj.; turn pale, pale.    deprive of color, decolorize, bleach, tarnish, achromatize, blanch, etiolate, wash out, tone down.    ... show more

Roget 653: be unclean, become unclean etc. adj.; rot, putrefy, ferment, fester, rankle, reek; stink etc. 401; mold, molder; go bad etc. adj.. render unclean etc. adj.; dirt, dirty; daub, blot, blur, smudge, smutch^†, soil, smoke, tarnish, slaver, spot, smear; smirch; begrease^†; dabble, drabble^†, draggle, daggle^†; spatter, slubber; besmear &c., bemire, beslime^†, begrime, befoul; splash, stain, distain^†, maculate, sully, pollute, defile, debase, contaminate, taint, leaven; corrupt etc. (injure) 659; cover with dust etc. n.; drabble in the mud^†; roil.    wallow in the mire; slobber, slabber^†.    ... show more

Dutch: bezoedelen, bevuilen