Tonicity
/ˌtɒnɪˈsɪti/noun
The state or quality of being tense, firm, or having a particular muscle tone or fluid concentration.
Did you know?Tonicity comes from the same ancient Greek root that gave us *tone*, and in medicine it describes the pressure-like pull that controls how water moves across cell membranes.
Etymological Timeline
Ancient Greek
Greek
tonos
“A stretching, tightening, or pitch in music”
Late Latin
Latin
tonicus
“Pertaining to tension or tone”
17th Century
English
tonic
“Relating to tone, tension, or a strengthening agent”
19th Century
English
tonicity
“The condition of having tone or tension, especially in physiology”
Modern English
English
tonicity
“The degree of osmotic pressure exerted across a membrane”