Las"si*tude (?), n. [L. lassitudo, fr. lassus faint, weary; akin to E. late: cf. F. lassitude. See Late.]
A condition of the body, or mind, when its voluntary functions are performed with difficulty, and only by a strong exertion of the will; languor; debility; weariness.
The corporeal instruments of action being strained to a high pitch . . . will soon feel a lassitude.
© Webster 1913.