Thrum (?), n. [OE. thrum, throm; akin to OD. drom, D. dreum, G. trumm, lump, end, fragment, OHG. drum end, Icel. �römr edge, brim, and L. terminus a limit, term. Cf. Term.] [Written also thrumb.] 1. One of the ends of weaver's threads; hence, any soft, short threads or tufts resembling these.
2. Any coarse yarn; an unraveled strand of rope.
3. (Bot.) A threadlike part of a flower; a stamen.
4. (Mining) A shove out of place; a small displacement or fault along a seam.
5. (Naut.) A mat made of canvas and tufts of yarn.
Thrum cap, a knitted cap. Halliwell. — Thrum hat, a hat made of coarse woolen cloth. Minsheu.