Reactive

Part of speech: adjective

Pronunciation: /ɹiːˈæktɪv/

Definitions

1. Tending to respond to situations or stimuli rather than acting with forethought or initiative
2. Being inclined to respond to external stimuli rather than initiating actions or plans displays a nature of immediate reaction
3. Characterized by the propensity to quickly respond to external conditions or stimuli instead of taking proactive measures

Etymology: "Reactive" is a plain formation: "react" with the suffix "-ive," which turns a verb into an adjective meaning having the tendency or quality of the action. The verb "react" comes from the Latin prefix "re-," meaning "back" or "again," joined to "act," from Latin "agere," "to drive, do, set in motion." So the core idea is driving something back in response to a push. The suffix has a longer road. It descends from Latin "-ivus," which passed through Old French "-if" and Middle English "-yf" before settling into the form "-ive" in English. That is why the ending sounds softer than the Latin spelling would suggest, and why many English adjectives with this ending came into the language through French. "Reactive" itself took shape in English as a natural adjective from "react," so its meaning followed the verb: first the sense of acting in return, then the everyday sense of responding quickly or readily to a stimulus, which is the sense the word carries today.

Synonyms: responsive, sensitive

Antonyms: inactive, unresponsive