noun.
A small knot or lump in thread, whether woven into cloth or not.
noun.
A knot or an excrescence on walnut and other trees, used for ornamental veneering.
To pick knots, loose threads, etc., from, as in finishing cloth; specifically, to pick (wool) by hand.
To cleanse (cloth), as with fullers' earth or a similar substance.
To welter.
noun.
A pimple.
Same as birl.