Vigor

n. [O. Fr. vigor, vigūr, N. Fr. vigueur, It. vigore, Pr., Sp., Pg., & Lat. vigor, from Lat. vigere, to be lively or strong.] 1. Active strength or force of body; physical force. The vigor of this arm was never vain. Dryden.

2. Strength of mind; intellectual force; energy; as, vigor of mind or intellect.
3. Strength or force in animal or vegetable nature; as, a plant grows with vigor.
4. Strength; energy; efficacy.

In the fruitful earth His beams, unactive else, their vigor find. Milton.