The Oxford Thesaurus An A-Z Dictionary of Synonyms - tap°v.

1) rap, knock, dab, strike, peck; drum, beat: Must you continually tap on the table with that blasted pencil?! --n. 2) rap, knock, dab, strike, peck, pat; tapping, tap-tap, rapping, knocking, pecking, beat, beating, patter, pattering: I felt a tap on my shoulder. The tap, tap, tap of the dripping water was driving me mad.