Strum \Strum\, v. t. & i. [imp. & p. p. {Strummed}; p. pr. & vb.
n. {Strumming}.] [Probably of imitative origin. Cf. {Thrum}.]
To play on an instrument of music, or as on an instrument, in
an unskillful or noisy way; to thrum; as, to strum a piano.
[1913 Webster]