Lethargy

1. noun

   a state of comatose torpor (as found in sleeping sickness)

   Similar: lassitude, sluggishness

2. noun

   weakness characterized by a lack of vitality or energy

   Similar: inanition, lassitude, slackness

3. noun

   inactivity; showing an unusual lack of energy

   “the general appearance of sluggishness alarmed his friends”

   Similar: languor, sluggishness, phlegm, flatness