the world > textiles and clothing > textiles > textile fabric or an article of textile fabric > textile fabric > [verb (intransitive)] > develop defects or irregularities (2)
pill1955
intransitive. Of a fabric (esp. a knitted fabric) or a garment: to become covered with small balls of fluff on the surface through wear or rubbing.
snag1970
intransitive. Of a fabric: to be rendered imperfect by a pulled thread.