Nonreactivity

Part of speech: noun

Definitions

1. The condition of being unresponsive or inactive in the presence of stimuli or changes in the surrounding environment
2. A state characterized by lack of response to external stimuli or absence of reactions in various contexts
3. The quality of remaining unaffected or showing no change when faced with external influences

Etymology: "Nonreactivity" is a plain formation: the prefix "non-," meaning "not," attached to "reactivity," so the whole word means the quality of not reacting. "Reactivity" itself comes from "reactive," which is built on "react," from Latin "re-" (back, again) plus "actus," the past participle of "agere" (to do, drive). Put together, the root sense is something driven back in response to something acting on it. The prefix does the real work here. English has long used "non-" as a productive tool for turning any noun or adjective into its negation, so "nonreactivity" can be coined whenever someone needs a clean term for the absence of a property. Its most common home is chemistry, where a substance's low tendency to undergo chemical change is a key property, but the word has spread into psychology, medicine and everyday speech.

Synonyms: inertness, passivity, non-responsiveness, stability, imperturbability

Antonyms: reactivity, responsiveness, sensitivity, instability, changeability