To mutilate the legs or feet of (a horse) in order to induce a particular gait.
Origin
From Middle English sor, from Old English sār ("ache, wound") and sār, from Proto-Germanic *sairaz (compare Dutch zeer ("sore, ache"), Danish sår ("wound")). (compare German sehr ("very")), from Proto-Indo-European *sh₂eyro-, enlargement of *sh₂ey- (compare Hittite ("anger"), Welsh hoed ("pain"), Ancient Greek αἱμωδία ("sensation of having teeth on edge")).