activation English · revision 39407

+ {{infobox|confidence=established|formation=derivation|attested=1883, Journal of the American Chemical Society|origins=la agō}}

+

+ ==Pronunciation==

+ * UK: /ˌæktɪˈveɪʃn̩/^(Wiktionary)

+ * US: /ˌæktəˈveɪʃən/^(Wiktionary)

+

+ ==Etymology==

+ It is formed [[af|en|activate|-ion]] (see [[m|en|-ation]]); compare [[fr|activation]] (1835).^(OED 2026)^(SOED 2002) The verb comes from [[active]] and the suffix [[m|en|-ate]] (1620s),^(Etymonline) and the adjective from [[la|āctīvus]], from [[m|la|āctus|t=a doing]], from [[m|la|agō|t=to drive, do]].^(Etymonline)^(AHD 2024)

+

+ ==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''.^(OED 2026) Etymonline dates the noun to 1906,^(Etymonline) while Merriam-Webster gives 1848.^(MWU 2024)

+

+ ==Semantic evolution==

+ The military sense, calling a unit or reservist into active service, is originally American and dates from 1939.^(OED 2026) In ''activation analysis'' a sample is made radioactive, usually by irradiation with neutrons, so that its elements can be measured.^(SOED 2002)

+

+ ==Timeline==

+ * 1848 – first known use according to Merriam-Webster.^(MWU 2024)

+ * 1883 – the process of activating, in chemistry.^(OED 2026)

+ * 1906 – Etymonline's date.^(Etymonline)

+ * 1939 – calling into active service (US).^(OED 2026)

+

+ ==Modern meaning==

+ ===Noun===

+ # The act or process of making something active or operative: ''the activation of the smoke alarm''.^(MWU 2024)^(OED 2026)

+ # ''(chemistry, biochemistry)'' The process of making a substance more [[reactive]].^(OED 2026)

+ # ''(physics)'' The process of making a stable element [[radioactive]] by bombarding it with [[neutron|alt=neutrons]] or protons.^(Wiktionary)^(SOED 2002)

+ # ''(military)'' The calling of a unit or reservist into active service.^(OED 2026)

+ # ''(marketing)'' The promotion of a brand through an event or campaign.^(Wiktionary)

+

+ ==Word family==

+ * [[nonactivation]]

+ * [[photoactivation]]

+ * [[activation analysis]]

+ * [[activation energy]]

+ * [[neutron activation analysis]]

+

+ ==Related words==

+ * [[act]]

+ * [[agent]]

+ * [[deactivate]]

+

+ ==References==

+ {{reflist}}