I. tar ‧ nish 1 /ˈtɑːnɪʃ $ ˈtɑːr-/ BrE AmE verb
[ Date: 1400-1500 ; Language: Old French ; Origin: ternir 'to make dull' ]
1 . [transitive] if an event or fact tarnishes someone’s ↑ reputation , record, image etc, it makes it worse:
His regime was tarnished by human rights abuses.
2 . [intransitive and transitive] if metals such as silver, ↑ copper , or ↑ brass tarnish, or if something tarnishes them, they become dull and lose their colour:
Gold does not tarnish easily.
tarnished silver spoons
II. tarnish 2 BrE AmE noun [singular, uncountable]
dullness of colour, or loss of brightness