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) Vigorously, Vigorousness.
Origin: Cf. OF. Vigoros, F. Vigoureux, LL. Vigorosus.