Also isosmotic. Physical Chemistry. noting or pertaining to solutions characterized by equal osmotic pressure.Compare hypertonic(def 2), hypotonic(def 2).
  1. noting or pertaining to a solution containing the same salt concentration as mammalian blood.
  2. noting or pertaining to a muscular contraction in which constant tension continues while the length of the muscle decreases, as during mechanical work.
Music. of or characterized by equal tones.

Origin of isotonic

1820–30; < Greek isóton(os) having equal accent or tone (see iso-, tone) + -ic
Related formsi·so·to·nic·i·ty [ahy-suh-tuh-nis-i-tee] /ˌaɪ sə təˈnɪs ɪ ti/, noun Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

Examples from the Web for isotonic

Historical Examples of isotonic

British Dictionary definitions for isotonic



physiol (of two or more muscles) having equal tension
(of a drink) designed to replace the fluid and salts lost from the body during strenuous exercise
Also: isosmotic (of two solutions) having the same osmotic pressure, commonly having physiological osmotic pressureCompare hypertonic, hypotonic
music of, relating to, or characterized by the equal intervals of the well-tempered scaleisotonic tuning
Derived Formsisotonicity (ˌaɪsəʊtəʊˈnɪsɪtɪ), noun
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Word Origin and History for isotonic

1828, from Greek isotonos "of level pitch; equally stretched," from iso- (see iso-) + tonos (see tenet).

Online Etymology Dictionary, © 2010 Douglas Harper

isotonic in Medicine




Of equal tension.
Having the same concentration of solutes as the blood.
Of or involving muscular contraction in which the muscle remains under relatively constant tension while its length changes.
Related formsi′so•to•nici•ty (-tə-nĭsĭ-tē) n.
The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.