activation

Etymology

It is formed from English activate + -ion (see -ation); compare French activation (1835).^[2][3] The verb comes from active and the suffix -ate (1620s),^[4] and the adjective from Latin āctīvus, from āctus (“a doing”), from agō (“to drive, do”).^[4][5]

Earliest recorded meaning

The process of making something active; in chemistry, of making a substance more reactive: 1883, in the Journal of the American Chemical Society.^[2] Etymonline dates the noun to 1906,^[4] while Merriam-Webster gives 1848.^[6]

Semantic evolution

The military sense, calling a unit or reservist into active service, is originally American and dates from 1939.^[2] In activation analysis a sample is made radioactive, usually by irradiation with neutrons, so that its elements can be measured.^[3]

Timeline

• 1848 – first known use according to Merriam-Webster.^[6]
• 1883 – the process of activating, in chemistry.^[2]
• 1906 – Etymonline's date.^[4]
• 1939 – calling into active service (US).^[2]

Modern meaning

Noun

1. The act or process of making something active or operative: the activation of the smoke alarm.
2. (chemistry, biochemistry) The process of making a substance more reactive.
3. (physics) The process of making a stable element radioactive by bombarding it with neutrons or protons.
4. (military) The calling of a unit or reservist into active service.
5. (marketing) The promotion of a brand through an event or campaign.

Word family

• nonactivation
• photoactivation
• activation analysis
• activation energy
• neutron activation analysis

Related words

• act
• agent
• deactivate

References

1. ^ a b Wiktionary, the free dictionary, https://en.wiktionary.org
2. ^ a b c d e Oxford English Dictionary Online (accessed March 2026), Oxford: Oxford University Press
3. ^ a b Shorter Oxford English Dictionary on Historical Principles (2002), 5th ed., ed. William R. Trumble and Angus Stevenson, Oxford: Oxford University Press
4. ^ a b c d Harper, Douglas. Online Etymology Dictionary, https://www.etymonline.com
5. ^ The American Heritage Dictionary of the English Language (online 2024), 5th ed., Boston: Houghton Mifflin Harcourt
6. ^ a b Merriam-Webster Unabridged Dictionary (2024), online ed., Springfield, Mass.: Merriam-Webster