The definition of somnolent is to be sleepy or drowsy, or something that causes sleepiness or drowsiness.(adjective)
A cold medicine that causes you to feel really groggy and tired is an example of something that could be described as somnolent.
See somnolent in Webster's New World College Dictionary
Origin: LME sompnolent < MFr < L somnolentus < somnus, sleep: see Somnus
See somnolent in American Heritage Dictionary 4
Origin: Middle English sompnolent
Origin: , from Old French
Origin: , from Latin somnolentus
Origin: : somnus, sleep; see swep- in Indo-European roots
Origin: + -olentus, abounding in.
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