Meaning of thoroughpin

thor•ough•pin

Pronunciation: (thûr'ō-pin", -u-pin", thur'-), [key]
— n. Vet. Pathol.
  1. an abnormal swelling just above the hock of a horse, usually appearing on both sides of the leg and sometimes causing lameness.
Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease.