a disease of the hock joint of horses in which enlargement occurs because of collected fluids (bog spavin), bony growth (bone spavin), or distention of the veins (blood spavin).
2.
an excrescence or enlargement so formed.
Origin: 1400–50; late ME spaveyne < OF (e)spavain, esparvain swelling < ?
disease of the hock joint of a horse, 1426, from M.Fr. espavain, probably from Frank. *sparwan "sparrow" (see sparrow), so called perhaps from comparison of the bird's awkward gait to that of a horse affected with spavin.
Main Entry: spav·in Pronunciation: 'spav-&n Function: noun : a bony enlargement of the hock of a horse associated with strain —spav·ined/-&nd/adjective
[spav-in] 
