Insomnia

google

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early 17th century: from Latin, from insomnis ‘sleepless’, from in- (expressing negation) + somnus ‘sleep’.

wiktionary

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From Latin in-(“without”) +‎ somnus(“sleep”, noun) +‎ -ia.

etymonline

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insomnia (n.)

"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.