I. tōˈnisəd.ē, -ətē, -i noun
( -es )
Etymology: tonic (I) + -ity
1. : the condition or property of possessing muscular, systemic, mental, or moral tone : vigor , health
2. : muscular tonus
3. : normal responsiveness of a plant to external stimuli
II. noun
: the osmotic pressure of a solution