Definition of flub
flubber n. one who flubs
Flubber can refer to:
flub something up
to mess something up; to ruin something. I saw you play in the tournament last Friday. You really flubbed it up, if you don't mind me saying so. You really flubbed up the tournament.
flub the dub
Inf. to fail to do the right thing. Martin is flubbing the dub with the fund-raising campaign. Please don't flub the dub this time.
to make an error. I flubbed up again!