a lack of energy or enthusiasm
lethargy - tiredness
The word ‘lethargy’ suggests a feeling of sluggishness or an aversion to activity. However, it does not mean laziness. Often such feelings are brought on by an illness or injury, whether physical or mental or from experiencing something draining.
Michael’s depression is a major factor in his continued feelings of lethargy.
The sweltering weather was making everybody feel lethargic. It was impossible to work in such conditions.
Sandra has been moving around quite lethargically since she picked up that nasty dose of flu.