EXERT v.
To put force, ability, or anything of the nature of an active faculty; to put in vigorous action; to bring into active operation; as, to exert the strength of the body, limbs, faculties, or imagination; to exert the mind or the voice.
FEEBLE a.
Wanting force, vigor, or efficiency in action or expression; not full, loud, bright, strong, rapid, etc.; faint; as, a feeble color; feeble motion. "A lady's feeble voice." Shak.
FORCE n.
Strength or energy of body or mind; active power; vigor; might; often, an unusual degree of strength or energy; capacity of exercising an influence or producing an effect; especially, power to persuade, or convince, or impose obligation; pertinency; validity; special signification; as, the force of an appeal, an argume…