Con`trac*til"i*ty (?), n.
The quality or property by which bodies shrink or contract.
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.
© Webster 1913.