To play unskilfully, or in a vulgar, noisy manner, on a stringed musical instrument of the lute or harp kind, as a guitar, banjo, or zither, or (by extension) on a pianoforte; thrum.To play upon carelessly or unskilfully, as a stringed instrument; produce by rough manipulation of musical chords.To produce a specified effect upon by strumming on a musical instrument.n. A strumming; a careless or discordant performance on a stringed instrument.