"beat or play time on, or announce by beating on, a drum," 1570s, from drum (n.). Meaning "to beat rhythmically or regularly" (with the fingers, etc.) is from 1580s. Meaning "force upon the attention by continual iteration" is by 1820. To drum (up) business, etc., is American English 1839, from the old way of drawing a crowd or attracting recruits. To drum (someone) out "expel formally and march out by the beat of a drum" is originally military, by 1766.