Which word describes someone who is lacking energy or vitality?

The word "languid" effectively describes someone who is lacking energy or vitality. It conveys a sense of weakness, fatigue, or a lack of physical strength that can manifest in a person’s demeanor or actions. When someone is described as languid, it implies that they may move slowly or have a tendency to be listless, often as a result of exhaustion or a lack of enthusiasm.

In contrast, the other options do not fit the description of someone devoid of energy. "Lascivious" pertains to someone who is driven by sexual desire, which has no connection to vitality or energy levels. "Liberal" relates to a political or philosophical stance concerning freedom and equality, not energy. "Lithe," while it refers to someone who is graceful and flexible, suggests agility and vitality rather than a lack of them. Thus, "languid" is the most appropriate choice for describing someone who is lacking in energy or vigor.