Definition from Wiktionary, the free dictionary
- (botany) Relating to plant movement classified by growth as opposed to mature reactions to exogenous stimuli in surrounding environment. Antonym: allassotonic
- (physiology) Of or involving muscular contraction against resistance in which the length of the muscle changes and the tension differs due to an increasing load or difference in leverage. Antonym in regard to movement is isometric. Antonym in regard to tonus is isotonic. Tonic movements (auxo or iso) are either concentric (working muscle shortens) or eccentric (working muscle lengthens).