definition of
invalidate

[1] #1 invalidate v. [annul, quash, void, avoid, nullify] declare invalid; "The contract was annulled"; "void a plea". wn

[2] #2 invalidate v. [cancel] make invalid for use; "cancel cheques or tickets". wn

[3] #3 invalidate v. [nullify] show to be invalid. wn

[4] #4 invalidate v. [void, vitiate] take away the legal force of or render ineffective; "invalidate a contract". wn