Transient

Transient is an adjective describing something temporary or short-lived, not lasting or permanent. It can apply to people, events, conditions, or phenomena. As a noun, transient can refer to a person who passes through a place briefly, or to a transient phenomenon in a system.

In science and engineering, a transient is a short-lived change in a system before it settles to a steady state. Electrical circuits experience transients when switching or during fault conditions; these may involve brief surges, ringing or overshoot. Transient analysis studies these responses, often using time-domain or Laplace-transform methods to understand peak values and damping.

In mathematics and physics, transient solutions describe components of a system's response that decay over time, in contrast to steady-state solutions. In stochastic processes, a transient state is one that may be left and never revisited with nonzero probability, unlike recurrent states.

In computing, transient data or fields are those not intended to be stored long-term. Some programming languages designate certain data as transient to exclude it from persistence, such as serialization. In databases, transient information may be cached or derived rather than stored.

The term is used across disciplines to emphasize temporariness, indicating that a condition, value, or state is not permanently fixed and may vary with time or context.