slub n 1: soft lump or unevenness in a yarn; either an imperfection or created by design [syn: {slub}, {knot}, {burl}]
Slub \Slub\, n. [Etymol. uncertain.] A roll of wool slightly twisted; a rove; -- called also {slubbing}. [1913 Webster]
Slub \Slub\, v. t. [imp. & p. p. {Slubbed}; p. pr. & vb. n. {Slubbing}.] To draw out and twist slightly; -- said of slivers of wool. [1913 Webster]