burl 
(bûrl)
(bûrl)n.
1. A knot, lump, or slub in yarn or cloth.
2.
a. A large rounded outgrowth on the trunk or branch of a tree.
b. The wood cut from such an outgrowth, often used decoratively as a veneer.
tr.v. burled, burl·ing, burls
To dress or finish (cloth) by removing knots, lumps, slubs, or loose threads.
[Middle English burle, from Old French bourle, tuft of wool, diminutive of bourre, coarse wool, from Late Latin burra, shaggy garment.]
burler n.