tarnish

UK: /ˈtɑː^rnɪʃ/ US: /ˈtɑrnɪʃ/ ,(tär′nish)

WordReference Random House Learner's Dictionary of American English © 2025

tar•nish /ˈtɑrnɪʃ/   v. 

1. Metallurgy to (cause a metal surface to) be dull;
   (cause to) be discolored: [~ + object]
   The salty ocean air tarnished her silver teapot.
   [no object]
   Silver tarnishes easily in salty air.
2. to destroy the good name of;
   stain;
   discredit:
   [~ + object] The charge of fraud tarnished the company's reputation.

n. [uncountable]

3. Metallurgy a tarnished coating.
4. Metallurgy tarnished condition;
   discoloration.

WordReference Random House Unabridged Dictionary of American English © 2025

tar•nish  (tär′nish), v.t. 

1. Metallurgy to dull the luster of (a metallic surface), esp. by oxidation;
   discolor.
2. to diminish or destroy the purity of;
   stain;
   sully:
   The scandal tarnished his reputation.

v.i. 

3. to grow dull or discolored;
   lose luster.
4. to become sullied.

n. 

5. Metallurgy a tarnished coating.
6. Metallurgy tarnished condition;
   discoloration;
   alteration of the luster of a metal.
7. a stain or blemish.

• Gmc; compare Old High German tarni, cognate with Old Saxon derni, Old English dierne hidden, obscure; see -ish²
• Middle French terniss-, long stem of ternir to dull, deaden, derivative of terne dull, wan
• 1590–1600

tar′nish•a•ble, adj. 
Synonyms

• 2. taint, blemish, soil.

Antonyms

• 1. brighten.

Collins Concise English Dictionary © HarperCollins Publishers::

tarnish / ˈtɑːnɪʃ/ verb

1. to lose or cause to lose the shine, esp by exposure to air or moisture resulting in surface oxidation; discolour
2. to stain or become stained; taint or spoil

noun

1. a tarnished condition, surface, or film

Etymology: 16th Century: 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

ˈtarnishable adjective