Source : Webster's Revised Unabridged Dictionary (1913)

Slub \Slub\, v. t. [imp. & p. p. {Slubbed}; p. pr. & vb. n.
   {Slubbing}.]
   To draw out and twist slightly; -- said of slivers of wool.

Source : WordNet®

slubbed
     adj : of textiles; having a rough surface; "a sweater knitted of
           nubbly homespun yarns" [syn: {homespun(p)}, {nubby}, {nubbly},
            {tweedy}]