In response, Netanyahu said Olmert was trying to tarnish his administration ahead of parliamentary elections next week.
And using charges themselves false in order to tarnish his reputation?
He said Iran pays lobbyists in Washington to discredit reports by Iranian exiles and tarnish their image.
1590s, from present participle stem of Middle French ternir "dull the luster or brightness of, make dim" (15c.), probably from Old French terne (adj.) "dull, dark," from a Germanic source cognate with Old High German tarnjan "to conceal, hide," Old English dyrnan "to hide, darken," from Proto-Germanic *darnjaz (see dern). Figurative sense is from 1690s. Related: Tarnished; tarnishing.
1713, from tarnish (v.).