Tendon \Ten"don\, n. [F., fr. L. tendere to stretch, extend. See {Tend} to move.] (Anat.) A tough insensible cord, bundle, or band of fibrous connective tissue uniting a muscle with some other part; a sinew. {Tendon reflex} (Physiol.), a kind of reflex act in which a muscle is made to contract by a blow upon its tendon. Its absence is generally a sign of disease. See {Knee jerk}, under {Knee}.