sluggish

Sluggish is an adjective that describes something moving, functioning, or responding more slowly than usual. It can refer to physical movement, mental alertness, energy levels, or the performance of a system, device, or process. A sluggish person may feel fatigued or unmotivated, while a sluggish machine shows delayed response or reduced efficiency.

In everyday language, the term is often used for temporary states, such as a sluggish morning after poor sleep, or a sluggish computer program that runs slowly due to high workload or hardware limitations. In medicine, people may describe feeling sluggish when fatigued or under the influence of sleep disorders, but persistent sluggishness warrants medical evaluation because it can be a symptom of underlying conditions such as anemia, thyroid disorders, infections, or sleep deprivation.

Sluggishness can also describe markets or economies that grow slowly, or processes that proceed with delay, such as a sluggish rollout of a service or a sluggish response to a request.

Related terms include lethargic, listless, slow, and languid; antonyms include brisk, energetic, and rapid. The noun form is sluggishness.