# isotonic

> English word · Adjective · IPA /ˌɑɪ.səˈtɑː.nɪk/ · frequency rank #92,738

## Definitions
1. Having the same osmotic pressure.
2. Having the same concentration of solutes as human blood.
3. Having equal tension.
4. Of or involving muscular contraction against resistance in which the length of the muscle changes. Antonym is isometric. Isotonic movements are either concentric (working muscle shortens) or eccentric (working muscle lengthens). See also Wikipedia:Isotonic (exercise physiology)
5. Having the same tone.

## Etymology
From iso- + tonic.

## Source
Compiled from Wiktionary via kaikki.org (CC BY-SA). Data vintage: 2026-05-06.
Canonical page: https://plainspell.com/en/word/isotonic