nontermal

Nontermal is not a standard term in scientific or technical literature. In most cases, it is a misspelling or variant of either nonthermal or non-terminal. When used as nonthermal, it denotes phenomena that do not arise from objects in thermal equilibrium.

In physics and astrophysics, nonthermal describes particle energy distributions that depart from a Maxwellian distribution. Such distributions occur when particles are accelerated by shocks, magnetic reconnection, turbulence, or other mechanisms. Nonthermal processes produce radiation with spectra that differ from blackbody emission, often following power laws.

Nonthermal radiation includes synchrotron, inverse Compton, and bremsstrahlung emissions not tied to a single temperature. In astronomy, nonthermal sources include supernova remnants, active galactic nuclei jets, and pulsar wind nebulae, characterized by broad, featureless spectra and usually significant polarization.

Nonthermal plasma refers to a state where electrons are hot relative to heavy particles but the overall plasma is not in thermodynamic equilibrium. This type of plasma is used in materials processing, surface treatment, and some medical applications.

In computing or grammar, non-terminal is a standard term for a symbol that can be replaced by a chain of other symbols in formal grammars; it is unrelated to the physical sense of nonthermal. If the term is encountered in other contexts, it may be a typographical error or a domain-specific neologism.