"chronic inability to sleep," 1620s, insomnie, from Latin insomnia "want of sleep, sleeplessness," from insomnis "sleepless," from in- "not" (see in- (1)) + somnus "sleep" (from PIE root *swep- "to sleep"). The re-Latinized form is from 1758.

Proto-Indo-European root meaning "to sleep."

It forms all or part of: hypno-; hypnosis; hypnotic; hypnotism; insomnia; somni-; somnambulate; somniloquy; somnolence; somnolent; Somnus; sopor; soporific.

It is the hypothetical source of/evidence for its existence is provided by: Sanskrit svapnah, Avestan kvafna-, Greek hypnos, Latin somnus, Lithuanian sapnas, Old Church Slavonic sunu, Old Irish suan, Welsh hun "sleep;" Latin sopor "a deep sleep;" Old English swefn, Old Norse svefn "a dream."

1877 (adj.); 1879 (n.), from insomnia. Earlier was insomnious (1650s).

"excessive sleeping or morbid sleepiness," 1863; see hyper- + ending from insomnia. Related: Hypersomniac.

1995, trade name for a powerful insomnia drug.

trade name for prescription medication Zolpidem, which is used to treat insomnia, registered 1993 in U.S., no doubt suggested by ambient or words like it in French.