(computing theory) A counter or variable that is incremented whenever an event of interest occurs, and also periodically decremented; used in algorithms to check whether events will gradually overflow the system's capacity, for example in a telecommunication network.

A leaky mode or tunneling mode in an optical fiber or other waveguide is a mode having an electric field that decays monotonically for a finite distance in the transverse direction but becomes oscillatory everywhere beyond that finite distance.

Mutation with partial loss function.

Memory management error causing leaks.

(alternative medicine) A supposed medical condition where an altered or damaged bowel lining or gut wall allows substances such as toxins, microbes, undigested food, or waste to leak through, triggering an immune reaction and leading to other disorders.

(software engineering) An abstraction that undesirably exposes details and limitations of its underlying implementation.

Leaky-wave antenna belong to the more general class of traveling wave antenna, that use a traveling wave on a guiding structure as the main radiating mechanism.

A leaky feeder is a communications system used in underground mines and inside tunnels.

The leaky homes crisis is an ongoing construction and legal crisis in New Zealand concerning timber-framed homes built from 1988 to 2004 that were not fully weather-tight.

The leaky condo crisis, also known as the leaky condo syndrome and rotten condo crisis, is an ongoing construction, financial, and legal crisis in Canada.

In mathematics, a leaky integrator equation is a specific differential equation, used to describe a component or system that takes the integral of an input, but gradually leaks a small amount of input over time.