isotonic

adj. of a solution which has the same osmotic pressure as another (Chemistry, Physiology); having equal tones (Music)

For Isotonic muscle exercise, see Isometric exercise and Weight training.For the term associated with muscle contraction, see isotonic (exercise physiology)For the term in nuclear physics, see isotoneIsotonic literally translates to equal tension. The term is used in several different contexts.Isotonic solution bears the same chemical resemblance of the body’s blood, plasma and tears. All fluids in the body have a certain concentration, referred to as osmotic pressure. The body’s common osmotic pressure, which is isotonic, allows a consistent maintenance of body tissues. In order for a substance to be absorbed and used in the body’s metabolism, it must be transported in an isotonic state.
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Adjective
1. (used of solutions) having the same or equal osmotic pressure
(synonym) isosmotic
(antonym) hypertonic
2. relating to or characterized by the equal intervals of the well-tempered scale; "isotonic tuning"
(pertainym) tone, whole tone, step, whole step
3. of or involving muscular contraction in which tension is constant while length changes
(antonym) isometric
(classification) physiology
4. of two or more muscles; having equal tension
(similar) tense
(classification) physiology

(a.)
Having or indicating, equal tones, or tension.
  

Refers to solutions that have equal osmotic pressure .