sprainv. t.[OF. espreindreto press, to force out, F. preindre, fr. L. exprimere. See Express, v. t., and cf. Spraints.] To weaken, as a joint, ligament, or muscle, by sudden and excessive exertion, as by wrenching; to overstrain, or stretch injuriously, but without luxation; as, to sprain one's ankle.()n. The act or result of spraining; lameness caused by spraining; as, a bad sprain of the wrist.()Sprain fracture (Med.), the separation of a tendon from its point of insertion, with the detachment of a shell of bone to which the tendon is attached.()