Con′trac‐til″i‐ty (?), n. 1. The quality or property by which bodies shrink or contract.
2. (Physiol.) The power possessed by the fibers of living muscle of contracting or shortening.
☞ When subject to the will, as in the muscles of locomotion, such power is called voluntary contractility; when not controlled by the will, as in the muscles of the heart, it is involuntary contractility.