Usage: "Somnolence" is primarily used as a noun. Its central meaning — a state of drowsiness or sleepiness — makes it most effective in contexts where precision matters over a more general alternative.
Origin: Borrowed from Middle French somnolence, from Late Latin somnolentia, derived from Latin somnus (“sleep”), from Proto-Indo-European *swépnos (“sleep, slumber”).
Watch out: Writers sometimes confuse "somnolence" with "sleepiness" or "drowsiness" — the words overlap in meaning but differ in nuance or register. Use "somnolence" when you specifically mean its core sense rather than defaulting to it as a generic substitute.
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Last reviewed May 2026.
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