The muscular part of the hind leg of a horse between the stifle and the hock.
- ‘A timid looking girl said, ‘It's the bone above the gaskin.’’
- ‘Go back down anatomically and I would certainly like to see big gaskins.’
- ‘The pelvis is one of some length while the femur is relatively short compared to the length of gaskin.’
Late 16th century: perhaps from galligaskins (the original sense).