delirious

Etymology

It is formed from English delirium + -ous.^{[2][3][4][5][6]} The noun is from Latin dēlīrium (“madness, derangement”),^[2][3] from dēlīrō (“to be deranged, rave”),^[2][3] literally to go off the furrow, a metaphor from ploughing,^[3][6] formed from dē- (“off, away”) and līra (“furrow”),^[3][6] from Proto-Indo-European *lois- (“track, furrow”),^[3] given by Ayto as *leis-.^[7] Klein compares German Gleis (“track”) and Old English lǣran (“to teach”), from a Germanic base he takes to have meant following a track, and Ayto makes the same link with learn and the verb last.^[6][7] Late Latin had an adjective dēlīriōsus (“laughable, foolish”), which the OED only compares.^[2] Johnson derived the English word from Latin delirius.^[8]

Earliest recorded meaning

Resembling delirium; irrational, absurd: 1599, in Master Broughtons Letters Answered.^[2][4] Etymonline gives 1703, with an earlier delirous in the 1650s.^[3]

Semantic evolution

The English word, formed on a noun known from the 1590s,^[3] was applied first to irrational talk and behaviour in general, and only from 1665 to the condition itself as a medical matter; "affected with delirium", of a patient, is first recorded about 1702.^[2] Johnson (1755) defined it as "light-headed; raving; doting".^[8] From the start it could also mean frenzied or wildly excited,^[2] a sense parallel to the "mad rapture" that Etymonline dates from the 1640s for delirium.^[3] In later use it has come to describe people who are wildly happy.^[2][9]

Timeline

• 1599 – irrational, absurd, frenzied.^[2][4]
• 1665 – in medicine, of or characteristic of delirium, in Nedham.^[2]
• 1673 – of a person, acting irrationally or in wild excitement.^[2] Etymonline dates the figurative sense to 1791.^[3]
• c. 1702 – of a patient, affected with delirium.^[2] The Shorter Oxford has the early 18th century, and Etymonline 1703.^[5][3]

Meanings

Adjective

1. Affected with delirium; confused in mind, as from a fever: The patient was delirious all night.^[9][4][2]
2. Of or typical of delirium: delirious ramblings.^[4][2]
3. Wildly excited, especially with joy: The crowd was delirious after the final whistle.^[9][2]
4. Tending to cause delirium or wild excitement.^[4]

Word family

• deliriously
• deliriousness
• nondelirious
• undelirious

Related words

• delirium
• learn
• last

References

1. ^ Wiktionary, the free dictionary, https://en.wiktionary.org
2. ^ a b c d e f g h i j k l m n o Oxford English Dictionary Online (accessed March 2026), Oxford: Oxford University Press
3. ^ a b c d e f g h i j k Harper, Douglas. Online Etymology Dictionary, https://www.etymonline.com
4. ^ a b c d e f Merriam-Webster Unabridged Dictionary (2024), online ed., Springfield, Mass.: Merriam-Webster
5. ^ a b Shorter Oxford English Dictionary on Historical Principles (2002), 5th ed., ed. William R. Trumble and Angus Stevenson, Oxford: Oxford University Press
6. ^ a b c d Klein, Ernest. A Comprehensive Etymological Dictionary of the English Language. 2 vols. Amsterdam: Elsevier, 1966–1967.
7. ^ a b Ayto, John (2005), Word Origins: The Secret Histories of English Words from A to Z, 2nd ed., London: A & C Black
8. ^ a b Johnson, Samuel (1755), A Dictionary of the English Language, London; 4th ed. 1773; Johnson's Dictionary Online, ed. Beth Rapp Young et al.
9. ^ a b c Collins English Dictionary (2023), Glasgow: HarperCollins