discoloration of metal surface caused by oxidation
make dirty or spotty, as by exposure to air; also used metaphorically; "The silver was tarnished by the long exposure to the air"; "Her reputation was sullied after the affair with a married man"
declare null and void; make ineffective; "Cancel the election results"; "strike down a law"
postpone indefinitely or annul something that was scheduled; "Call off the engagement"; "cancel the dinner party"; "we had to scrub our vacation plans"; "scratch that meeting--the chair is ill"
make up for; "His skills offset his opponent's superior strength"