saddle sore noun 2adjective 1forms 3 noun2 •A gall, a sore developed by a horse from an ill-fitting or ill-adjusted saddle. •A sore developed by a horseback rider or a cyclist caused by a saddle. adjective1 •Pertaining to a horse with saddle sores, or to a rider who has been riding too long. formssaddle sores · more saddle sore · most saddle sore