n. a notation cancelling a previous sharp or flat

n. the act of cancelling an operation

v. make invalid for use; "cancel cheques or tickets"

v. remove or make invisible; "Please delete my name from your list"

v. declare null and void; make ineffective; "Cancel the election results"; "strike down a law"

v. 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"

v. make up for; "His skills offset his opponent's superior strength"

v. (undo)