fetlock
n.
5ME fitlok (understood in ME as comp. of fet, FEET + lok, LOCK2) < MDu or MLowG cognate of MHG vizzeloch < vissel, dim. (< base of OHG fuoz, FOOT) + 3och, 3OCK6
1 a tuft of hair on the back of the leg of a horse, donkey, etc., just above the hoof
2 the joint or projection bearing this tuft See HORSE, illus.