verb (used with object), ac·ti·vat·ed, ac·ti·vat·ing.
- to make active; cause to function or act.
- to render more reactive; excite: to activate a molecule.
- to induce radioactivity.
- to aerate (sewage) in order to accelerate decomposition of impure organic matter by microorganisms.
- to make (carbon, a catalyst, molecules, etc.) more active.
- to hasten (reactions) by various means, as heating.
- to place (a military unit or station) on an active status in an assigned capacity.
- to make active or capable of action
- physics to make radioactive
- to increase the rate of (a reaction)
- to treat (a substance, such as carbon or alumina) so as to increase powers of adsorption
- physiol to prepare by arousal (the body or one of its organs (e.g. the brain)) for action
- to purify (sewage) by aeration
- US military to create, mobilize, or organize (a unit)
1906, noun of action from activate (v.).