Energetic, Energetical, a.
Etymology: [Gr. Energy.]
1. Having energy or energies; possessing a capacity for vigorous action or for exerting force; active. "A Being eternally energetic." Grew.
2. Exhibiting energy; operating with force, vigor, and effect; forcible; powerful; efficacious; as, energetic measures; energetic laws.
Syn. -- Forcible; powerful; efficacious; potent; vigorous; effective; strenuous. -- En`er*get"ic*al*ly, adv. -- En`er*get"ic*al*ness, n.
Shades of meaning
Fernald has no entry of its own for energetic; he lists it under active.
He lists it without comment; the entries above explain its neighbors.