somnolence

n. sleepiness, drowsiness, desire to sleep

Somnolence (or "drowsiness") is a state of near-sleep, a strong desire for sleep, or sleeping for unusually long periods. It has two distinct meanings, referring both to the usual state preceding falling asleep, and the chronic condition referring to being in that state independent of a circadian rhythm. The disorder characterized by the latter condition is most commonly associated with users of prescription hypnotics, such as mirtazapine or zolpidem.
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Somnolence /som·no·lence/ drowsiness or sleepiness, particularly in excess. som·no·lence n. 1. A state of drowsiness; sleepiness. 2. [more]Somnolence - Community and Resources

Noun
1. a very sleepy state; "sleepiness causes many driving accidents"
(synonym) sleepiness, drowsiness
(hypernym) temporary state
(hyponym) oscitancy, oscitance

n. somnolency, drowsiness, sleepiness