Momentary

Momentary is an English adjective meaning lasting for a very short time or occurring for a brief instant. It describes events, states, or impressions that are temporary and not enduring, such as a momentary pause, a momentary lapse, or momentary confusion. In everyday use, the term emphasizes brevity rather than frequency, and it is commonly applied to both physical phenomena and mental or perceptual experiences.

In technical and engineering contexts, momentary also describes devices or actions that are active only while an external force is applied. A momentary switch, for example, closes a circuit only while it is pressed, and returns to its resting state when released. This is contrasted with latching devices that hold their state after actuation.

Etymology traces momentary to moment plus the suffix -ary, with roots in Latin momentum and Old French influence. The word is often used interchangeably with synonyms such as brief, transient, ephemeral, or temporary, though each term carries subtle nuances.

Usage notes include a potential ambiguity with the adverb momentarily, which can mean “for a moment” or, less commonly, “in a moment.” Context usually clarifies intent, but writers should be aware of regional variations in usage.

Overall, momentary conveys the idea of a fleeting, nonpermanent occurrence, whether describing a short-lived event, a temporary condition, or a short-duration mechanism in engineering.