[ dee-ak-tuh-veyt ]
/ diˈæk təˌveɪt /

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.


Origin of deactivate

First recorded in 1900–05; de- + activate
Related formsde·ac·ti·va·tion, nounde·ac·ti·va·tor, noun Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

Examples from the Web for deactivate

  • Conn used the manual control to set it down and deactivate it, then got out and went to examine it.

    The Cosmic Computer|Henry Beam Piper
  • It will not be possible to deactivate it before 12.45 hours.

    The Lost Kafoozalum|Pauline Ashwell

British Dictionary definitions for deactivate


/ (diːˈæktɪˌveɪt) /


(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
Derived Formsdeactivation, noundeactivator, noun
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Word Origin and History for deactivate



1904, from de- + activate. Related: Deactivated; deactivating; deactivation.

Online Etymology Dictionary, © 2010 Douglas Harper