lethargy

The story

1. Ancient Greek · derived fromληθᾱργῐ́ᾱ“drowsiness”
2. Late Latin · derived fromlēthārgia
3. Medieval Latin · derived fromlitargia
4. Middle English · inherited fromlitargie
5. English todaylethargy

From Middle English litargie, from Medieval Latin litargia, from Late Latin lēthārgia, borrowed from Ancient Greek ληθᾱργῐ́ᾱ (lēthārgĭ́ā, “drowsiness”), from λήθᾱργος (lḗthārgos, “forgetful, lethargic”) + -ῐ́ᾱ (-ĭ́ā, adjectival suffix).

First known use, by meaning

• from 14th c. A state of extreme torpor, sopor or apathy, especially with lack of emotion, energy or enthusiasm; (loosely) sluggishness, laziness.
• from 14th c. A condition characterized by extreme fatigue or drowsiness, deep unresponsiveness, or prolonged sleep patterns.