burl

The story

1. Medieval Latin · derived fromburra“flock of wool, coarse hair”
2. Old French · derived frombourre
3. Old French · derived frombourle“flocks or ends of threads which disfigure cloth”
4. Middle English · inherited fromburle“a knot or flaw in cloth”
5. English todayburl

From Middle English burle (“a knot or flaw in cloth”), from Old French bourle (“flocks or ends of threads which disfigure cloth”), diminutive of Old French bourre, from Medieval Latin burra (“flock of wool, coarse hair”).