*lois-

1703, "wandering in the mind, affected with delirium" (as a result of fever or illness), from stem of delirium + -ous. The earlier adjective was delirous (1650s). Figurative sense of "characterized by or proceeding from wild excitement or exaggerated emotion" is by 1791. Related: Deliriously; deliriousness.

1590s, "a disordered state, more or less temporary, of the mind, often occurring during fever or illness," from Latin delirium "madness," from deliriare "be crazy, rave," literally "go off the furrow," a plowing metaphor, from phrase de lire, from de "off, away" (see de-) + lira "furrow, earth thrown up between two furrows," from PIE root *lois- "track, furrow." Meaning "violent excitement, mad rapture" is from 1640s.

Delirium tremens (1813) is medical Latin, literally "trembling delirium," introduced 1813 by British physician Thomas Sutton for "that form of delirium which is rendered worse by bleeding, but improved by opium. By Rayer and subsequent writers it has been almost exclusively applied to delirium resulting from the abuse of alcohol" ["The New Sydenham Society's Lexicon of Medicine and the Allied Sciences," London, 1882]. As synonyms, Farmer lists barrel-fever, gallon distemper, blue Johnnies, bottle ache, pink spiders, quart-mania, snakes in the boots, triangles, uglies, etc.