Lethargic state is a condition characterized by extreme mental and physical sluggishness. It can be caused by a variety of factors, including depression, illness, or medication. Three words that describe this condition are STUPOR, TORPOR, and SOPOR. STUPOR is a state of near-unconsciousness, in which the person is unresponsive to external stimuli. TORPOR is a state of decreased physical activity and decreased responsiveness to stimuli. SOPOR is a state of deep sleep, in which the person is unresponsive to external stimuli. All three words describe a lethargic state, in which the person is unresponsive to external stimuli and has decreased physical activity.