depleted

Depleted is an adjective used to describe something that has been drained, exhausted, or reduced in amount, quality, or strength. It widely applies to natural resources, energy, budgets, and physical materials, as well as to abstract quantities such as confidence or morale. When a substance or system is depleted, its remaining capacity or content is lower than before.

In technical contexts, depletion refers to the removal or reduction of a component. For example, a depleted uranium sample has had most of its fissile isotope U-235 removed, leaving mainly U-238. In electronics, the depletion region around a p-n junction is a zone where mobile charge carriers are scarce, created by the built-in electric field.

Resource depletion is a major topic in economics and environmental science, describing the diminishing availability of natural resources as they are consumed faster than they are replenished. In pharmacokinetics, depletion describes the decline of a drug's concentration in the body over time. In everyday language, a battery can become depleted after use, indicating it no longer holds necessary charge.

Etymology: the word depleted derives from the Latin de- (away) and plere (to fill), indicating the removal or reduction of contents. Related terms include depletion, exhaust, drain, consume, and exhaustion, used across disciplines to describe diminishing stocks, energy, or capability.