# tonicity

> English word · Noun · IPA /təˈnɪsɪti/

## Definitions
1. The normal presence of tone or tension in a muscle or organ; tonus
2. The ability of nonpenetrable solutes in a solution to exert an osmotic pressure upon a membrane

## Etymology
From tonic + -ity.

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