Pronunciation: (ak'tu-vāt"), [key]
—v.t., -vat•ed, -vat•ing.
1. to make active; cause to function or act.
a. to render more reactive; excite: to activate a molecule.
b. to induce radioactivity.
3. to aerate (sewage) in order to accelerate decomposition of impure organic matter by microorganisms.
a. to make (carbon, a catalyst, molecules, etc.) more active.
b. to hasten (reactions) by various means, as heating.
5. to place (a military unit or station) on an active status in an assigned capacity.
Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease.