unchannelled

Unchannelled is an adjective meaning not channeled or not having a channel. It is used in British English as unchannelled and in American English as unchanneled. The sense is either literal — lacking a defined watercourse or drainage channel — or figurative — not directed through a particular route or medium.

In hydrology and geomorphology, unchannelled describes landscapes or flows that do not follow a single defined channel. For example, unchannelled sheet flow distributes over a floodplain rather than within a single channel, and unchannelled drainage refers to diffuse runoff that has not been organized into channels. In planning and engineering, unchannelled conditions can influence flood risk and sediment transport, and may contrast with channelled or piped drainage systems.

In other uses, the term may describe energy, information, or impulses that are not transmitted through an established channel, or emotions not directed toward a specific outlet. Because the term is not widely standardized, it is seen mainly in technical or historical texts.

Originates from the base noun channel, via un- prefix; British form often retains double l in channelled spellings (unchannelled) whereas American spellings (unchanneled) drop the extra l in channeled.