(thrum) v. thrummed, thrum·ming v.t.
1. To play on or finger (a stringed instrument) idly and without expression.
2. To drum or tap monotonously or listlessly.
3. To recite or repeat in a droning, monotonous way.
—v.i.
4. To thrum a stringed instrument.
5. To sound when played thus, as a guitar.
6. Scot. To purr.
—noun Any monotonous drumming. [Prob. imit.]

(thrum) noun
1. The fringe of warp threads remaining on a loom beam after the web has been cut off; also, one of such threads.
2. Any loose thread or fringe, or a tuft of filaments or fibers; a tassel.
3. plural Coarse or waste yarn.
4. plural Naut. Bits of rope yarn for sewing on canvas to make chafing gear or collision mats.
5. Bot. A threadlike organ or part of a flower; stamen.
6. Scot. A bit; particle: I don't care a thrum.
7. Scot. A tangle.
—v.t. thrummed, thrum·ming.
1. To cover or trim with thrums or similar appendages.
2. Naut. To insert bits of rope yarn in (canvas) to produce a rough surface or mat to be used to prevent chafing. [OE -thrum ligament, as in tungethrum the ligament of the tongue]