verb (used with object), de·ac·ti·vat·ed, de·ac·ti·vat·ing.
- to cause to be inactive; remove the effectiveness of.
- to demobilize or disband (a military unit).
- to render (a bomb, shell, or the like) inoperative, especially by disconnecting, removing, or otherwise interfering with the action of the fuze.
- Chemistry. to render (a chemical, enzyme, catalyst, etc.) inactive.
verb (used without object), de·ac·ti·vat·ed, de·ac·ti·vat·ing.
- Physical Chemistry. to lose radioactivity.
verb
- (tr) to make (a bomb, etc) harmless or inoperative
- (intr) to become less radioactive
- (tr) US to end the active status of (a military unit)
- chem to return or cause to return from an activated state to a normal or ground state
1904, from de- + activate. Related: Deactivated; deactivating; deactivation.