Vigorous \Vig"or*ous\, a. [Cf. OF. vigoros, F. vigoureux, LL. vigorosus.]

1. Possessing vigor; full of physical or mental strength or active force; strong; lusty; robust; as, a vigorous youth; a vigorous plant.

Famed for his valor, young, At sea successful, vigorous and strong. --Waller.

2. Exhibiting strength, either of body or mind; powerful; strong; forcible; energetic; as, vigorous exertions; a vigorous prosecution of a war.

The beginnings of confederacies have been always vigorous and successful. --Davenant. -- Vig"or*ous*ly, adv. -- Vig"or*ous*ness, n.

Source: Webster's Revised Unabridged Dictionary (1913)