definition for deactivation
deÂ·acÂ·tiÂ·vate. tr.v. deÂ·acÂ·tiÂ·vatÂ·ed, deÂ·acÂ·tiÂ·vatÂ·ing, deÂ·acÂ·tiÂ·vates. 1. To render inactive or ineffective. 2. To inhibit, block, or disrupt the action of (an enzyme or other biological agent). 3. To remove from active military status.