slub, n. & adj.
1 a lump or thick place in yarn or thread.
2 fabric woven from thread etc. with slubs.
--adj. (of material etc.) with an irregular appearance caused by uneven thickness of the warp.
slub, n. & v.
--n. wool slightly twisted in preparation for spinning.
--v.tr. (slubbed, slubbing) twist (wool) in this way.
18th c.: orig. unkn.