Which word best describes a person who lacks energy and is sluggish?

The word "torpid" accurately describes a person who lacks energy and is sluggish. Derived from Latin, "torpid" conveys the idea of being inactive, lethargic, or apathetic, often implying a state of physical or mental sluggishness. This term captures the essence of someone who feels heavy and unenergetic, reflecting an overall lack of vitality.

In contrast, the other options present different characteristics. "Urbane" refers to a person who is sophisticated, polished, and well-mannered, indicating a sense of energy in social contexts. "Witty" describes someone sharp and clever in humor or conversation, reflecting a lively and quick-minded demeanor. "Sullen" characterizes an individual who is gloomy or silently ill-humored, but it does not specifically imply a lack of overall energy in the same way "torpid" does. Thus, "torpid" stands out as the most fitting word to describe someone who is sluggish and devoid of energy.