A horse's fetlock is the back part of its leg, just above the hoof.
fetlock in British English
(ˈfɛtˌlɒk) or fetterlock
noun
1.
a projection behind and above a horse's hoof: the part of the leg between the cannon bone and the pastern
2. Also called: fetlock joint
the joint at this part of the leg
3.
the tuft of hair growing from this part
Word origin
C14 fetlak; related to Middle High German vizzeloch fetlock, from vizzel pastern + -och; see foot
fetlock in American English
(ˈfɛtˌlɑk)
noun
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
Word origin
ME 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) + -och, -ock
Examples of 'fetlock' in a sentence
fetlock
We'll have to poultice the beast's right front fetlock, but he'll be fine.
Julian May IRONCROWN MOON: PART TWO OF THE BOREAL MOON TALE (2004)