Spavin \Spav"in\, n. [OE. spaveyne, OF. esparvain, F. ['e]parvin; akin to OF. espervier a sparrow hawk, F. ['e]pervier, fr. OHG. sparw[=a]ri (G. sperber), fr. OHG. sparo sparrow, because this disease makes the horse raise the infirm leg in the manner of a sparrow hawk or sparrow. See Sparrow.]

(Far.) A disease of horses characterized by a bony swelling developed on the hock as the result of inflammation of the bones; also, the swelling itself. The resulting lameness is due to the inflammation, and not the bony tumor as popularly supposed. --Harbaugh.

Bog spavin, a soft swelling produced by distention of the capsular ligament of the hock; -- called also blood spavin.

Bone spavin, spavin attended with exostosis; ordinary spavin.

Source: Webster's Revised Unabridged Dictionary (1913)