adj ·Uncommon ·Advanced level

Definitions

Adjective

1. 1
   Having the same osmotic pressure. not-comparable
2. 2
   Having the same concentration of solutes as human blood. not-comparable

   "Use an isotonic saline solution in your neti pot to prevent irritation of your nasal passages."

3. 3
   Having equal tension. not-comparable
4. 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) not-comparable
5. 5
   Having the same tone. not-comparable

Adjective

1. 1
   of or involving muscular contraction in which tension is constant while length changes wordnet
2. 2
   (used of solutions) having the same or equal osmotic pressure wordnet
3. 3
   of two or more muscles; having equal tension wordnet
4. 4
   relating to or characterized by the equal intervals of a musical scale wordnet

Synonyms

All synonyms

isosmotictense

Antonyms

All antonyms

auxotonichypertonichypotonicisometric

Example

More examples

"Isotonic drinks are actually hypotonic."

Etymology

From iso- + tonic.

Related phrases

isotonic contractionosmotic pressure

Data sourced from Wiktionary, WordNet, CMU, and other open linguistic databases. Updated March 2026.