fetlock

• fetterlock, fewterlock (dialectal)

From Middle English fitlokes, feetlakkes pl, equivalent to foot +‎ lock (“tuft of hair”). Cognate with Dutch vitlok, vittelokke, vitslok, German Fissloch, Fisloch, Fislach (“fetlock; pastern”).

fetlock (plural fetlocks)

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

   Synonym: ankle

   • 1902, John Buchan, The Outgoing of the Tide:

     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.