Lethargy (noun)

A state of sluggishness, drowsiness, or apathy; lack of energy or enthusiasm.

Origin:

From the middle english letargie, from old french letargie, from latin lethargia, from greek lethargia "drowsiness, dullness", from lethargos "sluggish, forgetful".

Examples:

1. The patient was suffering from lethargy and fatigue.
2. The prolonged lethargy of the economy is causing concern.
3. The heat wave caused lethargy and made it difficult for people to be active.
4. He couldn't shake off the lethargy that was weighing him down.
5. The medication caused a state of lethargy that lasted for several hours.