lethargy

Where does the word "lethargy" come from? It comes from Greek lēthargia, passing through Latin and Old French before entering English (1300s).

Lethargy’s story begins in Greek: lēthargia meant “forgetful sleep.” Drowsiness, from 'lēthē', forgetfulness, the river of oblivion in the underworld. By ancient, the word had taken hold in Latin as lethargia. A medical term for morbid drowsiness. From there it passed into Old French as litargie by medieval. A sleeping sickness. It reached English by 1300s as lethargy. Used in medicine before it meant ordinary sluggishness. Today, lethargy means a lack of energy and enthusiasm.

1. Stage 1 · Greek · ancient lēthargia "forgetful sleep", drowsiness, from 'lēthē', forgetfulness, the river of oblivion in the underworld.
2. Stage 2 · Latin · ancient lethargia "lethargy", a medical term for morbid drowsiness.
3. Stage 3 · Old French · medieval litargie "lethargy", a sleeping sickness.
4. Stage 4 · English · 1300s lethargy "lack of energy", used in medicine before it meant ordinary sluggishness.