lethargic
adj.adj. feeling very tired and lacking energy. You use this to describe someone who is slow to move or act because they are exhausted.
adj. characterised by a lack of energy, enthusiasm, or activity. Often describes a state of physical or mental fatigue that inhibits movement or response.
He felt lethargic after eating a large meal.
The patient remained lethargic for several hours after the surgery, showing little interest in the world around him.
The economy entered a lethargic phase, with businesses delaying investments and consumers tightening their budgets in anticipation of further interest rate hikes.
Learned borrowing from Ancient Greek ληθαργικός (lēthargikós), from λήθαργος (lḗthargos, “forgetful, lethargic”), from λήθη (lḗthē, “a forgetting, forgetfulness”) (from which Lethe (“river in Hades”)) + ἀργός (argós, “not working”). By surface analysis, lethargy + -ic.