deactivate

Etymology

It is formed from English de- + activate,^{[2][3][4][5][6]} with de- in the sense "do the opposite of".^[3] The verb activate is from active and -ate, recorded from the 1620s; its sense "to put into action" dates from 1902, at first in chemistry.^[3]

Earliest recorded meaning

To render inactive or less active: 1904, according to Etymonline.^[3] The OED's first quotation for the noun deactivation, hyphenated as de-activation, is from the same year, in the Scientific American Supplement;^[2] its first quotation for the verb, in a chemical sense, is from 1938.^[2]

Semantic evolution

Like activate in its modern sense, the verb began in science: the OED defines it chiefly as making something less chemically reactive, for instance a catalyst or an enzyme.^[2][4][3] The Historical Thesaurus places the general sense "to make inactive" from 1970.^[7] Other uses grew up around it: making a bomb or mine incapable of exploding,^[4][8] and, in American military use, disbanding a unit or ending its active status.^[4][8] Collins also records an intransitive sense, to become less radioactive.^[8]

Timeline

• 1904 – to make inactive or less active.^[3] Merriam-Webster Unabridged dates this sense to 1926.^[4]
• 1938 – in chemistry, to deprive of chemical action, to make less reactive.^[2][7]
• 1970 – to make inactive, outside chemistry.^[7]

Meanings

Verb

1. To make inactive or ineffective: She deactivated the alarm before opening the door.^[4][2][8]
2. To make a bomb or mine incapable of exploding; to make harmless.^[4][8]
3. (US) To disband a military unit, or end its active status.^[8][4]
4. (chemistry) To deprive of chemical activity; to make less reactive.^[4][2][8]
5. (intransitive) To become less radioactive.^[8]

Word family

• deactivation
• deactivator

Related words

• activate
• active

References

1. ^ Wiktionary, the free dictionary, https://en.wiktionary.org
2. ^ a b c d e f g Oxford English Dictionary Online (accessed March 2026), Oxford: Oxford University Press
3. ^ a b c d e f Harper, Douglas. Online Etymology Dictionary, https://www.etymonline.com
4. ^ a b c d e f g h i Merriam-Webster Unabridged Dictionary (2024), online ed., Springfield, Mass.: Merriam-Webster
5. ^ Shorter Oxford English Dictionary on Historical Principles (2002), 5th ed., ed. William R. Trumble and Angus Stevenson, Oxford: Oxford University Press
6. ^ Dictionary.com Unabridged (2016), based on the Random House Unabridged Dictionary, New York: Random House
7. ^ a b c Kay, Christian; Roberts, Jane; Samuels, Michael; Wotherspoon, Irené, eds. (2009), Historical Thesaurus of the Oxford English Dictionary, Oxford: Oxford University Press; online edition (2024)
8. ^ a b c d e f g h Collins English Dictionary (2023), Glasgow: HarperCollins