unmelted

Unmelted is an adjective used to describe a substance or portion of a substance that has not melted, or has not reached its melting point, under the current conditions. It can apply to solids such as ice, wax, metals, or polymers that remain in the solid phase while surrounding material may liquefy. The term is often used to distinguish between solid and liquid states during heating, cooling, or phase-change processes.

In scientific contexts, unmelted materials remain solid at temperatures where a melt would form. This concept is central to discussions of melting points, phase transitions, and heat treatment. For example, unmelted ice would persist when a surface below the melting point keeps its structure even as nearby liquid water exists. In geology and meteorology, unmelted snow or ice may refer to layers or pockets that survive seasonal warming, contributing to snowpack and glacier dynamics.

Etymology-wise, unmelted is formed from the prefix un- meaning not, and melted, the past participle of melt. The word conveys a straightforward negation of melting and is used across scientific, technical, and everyday language to contrast solid-state material with its liquid form.

See also: melting point, phase transition, solid-state, solidification.