fetlock

noun

Etymology: From Middle English fitlokes, feetlakkes pl, taken to be foot + lock (“tuft of hair”) but actually a misdivision of Old English -oc. Cognate with Middle Low German fitlok, fitlock (“fetlock”), Dutch vitlok, vittelokke, vitslok, German Fissloch, Fisloch, Fislach (“fetlock; pastern”).

1. A joint of the horse's leg below the knee or hock and above the hoof.

   “It was the better part of a mile wide, but save for some fathoms in the middle, where the Sker current ran, it was no deeper even at flood than a horse's fetlocks.”

2. The tuft of hair that grows at this joint.