from The American Heritage® Dictionary of the English Language, 4th Edition
- n. A condition of bodily strength, vigor, or vitality.
from Wiktionary, Creative Commons Attribution/Share-Alike License
- n. strength, vigour or vitality
from The Century Dictionary and Cyclopedia
- n. In pathology, strength; excessive force: opposed to asthenia or debility.
He assumed that the interaction between the excitability with which the body was endowed and the stimuli, external and internal, which it encountered during life determined health and the contrasting conditions of asthenia and sthenia.
Diseases occur according to increase or dimunition of the stimuli causing increased excitability, (sthenia) and weak stimuli diminished excitability (asthenia).