c. 1300, "immediate influence of God or a god," especially that under which the holy books were written, from Old French inspiracion "inhaling, breathing in; inspiration" (13c.), from Late Latin inspirationem (nominative inspiratio), noun of action from past-participle stem of Latin inspirare "blow into, breathe upon," figuratively "inspire, excite, inflame," from in- "in" (from PIE root *en "in") + spirare "to breathe" (see spirit (n.)). ,
And the Lord God formed man of the dust of the ground, and breathed into his nostrils the breath of life; and man became a living soul. [Genesis ii.7]
The sense evolution seems to be from "breathe into" to "infuse animation or influence," thus "affect, rouse, guide or control," especially by divine influence. Inspire (v.) in Middle English also was used to mean "breath or put life or spirit into the human body; impart reason to a human soul." Literal sense "act of inhaling" attested in English from 1560s. Meaning "one who inspires others" is attested by 1867.
"tending to inspire," 1878; see inspiration + -al (1). Also "influenced by inspiration" (1839); "pertaining to inspiration" (1888). The adjective was used earlier in spiritualism. Earlier in the sense "tending to inspire" were inspirative (1770), inspiring (1640s).
fount on Mount Helicon sacred to the Muses, its waters were held to bestow poetic inspiration, from Greek Hippokrene, earlier hippou krene, literally "horse's fountain," from genitive of hippos "horse" (from PIE root *ekwo- "horse") + krēnē "fountain," which is of uncertain origin.
mountain in Boeotia, sacred to the Muses, on which arose the fountains of Aganippe and Hippocrene, 1520s, from Latinized form of Greek Helikon, literally "the tortuous mountain," from helix (genitive helikos) "spiral," from PIE root *wel- (3) "to turn, revolve." Used allusively in reference to poetic inspiration. Related: Heliconian.
1660s, member of the Protestant sect founded c. 1651 by English tailor Lodowicke Muggleton (1609-1698) and John Reeve. Members believed in the prophetic inspiration of the two founders as being the two witnesses mentioned in Revelation xi.3-6. Members were still living in the 1860s.
"miraculous communication of supernatural knowledge or power," 1660s, from Latin afflatus "a breathing upon, blast," figuratively "inspiration," noun use of past participle of afflare "to blow upon," from ad "to" (see ad-) + flare "to blow" (from PIE root *bhle- "to blow"). The literal meaning "a blowing or breathing upon" is rare in English, this sense being taken by afflation.