readily partaking in chemical reactions: sodium is a reactive metal, free radicals are very reactive of, concerned with, or having a reactance responsive to stimulus (of mental illnesses) precipitated by an external cause (esp of a business or organization) tending to react to events rather than initiate change
WordReference Random House Unabridged Dictionary of American English © 2025
re•ac•tive
(rē ak′tiv),USA pronunciation adj.
re•ac′tive•ly, adv.
re•ac′tive•ness, n.
- tending to react.
- pertaining to or characterized by reaction.
- Electricitypertaining to or characterized by reactance.
- react + -ive 1705–15
re•ac′tive•ness, n.
Collins Concise English Dictionary © HarperCollins Publishers::
'reactive' also found in these entries (note: many are not synonyms or translations):
C-reactive protein
- CRP
- activate
- alkali metal
- atomic hydrogen
- baryta
- cesium
- cross-resistance
- dysprosium
- europium
- fluorine
- free radical
- immunoassay
- lifetime
- mean life
- oxygen
- passivate
- phosphorus
- photochemical smog
- potassium
- reaction turbine
- reactive component
- reactive depression
- reactive schizophrenia
- reactivity
- reagin
- rubidium
- sodium
- thrust
- turbine
- water turbine
- wattless component