[n] a notation cancelling a previous sharp or flat
[v] of 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"
[v] make up for; "His skills offset his opponent's superior strength"