uncrossable

Uncrossable is an adjective used to describe something that cannot be crossed or traversed. It is commonly applied to physical barriers such as rivers, cliffs, walls, or fences that block passage, as well as to obstacles that make crossing impractical or impossible for a given mode of movement.

In geography and transportation planning, areas or routes may be labeled uncrossable to indicate that crossing is prohibited or infeasible without a substantial detour, specialized equipment, or alternative infrastructure. The status can be conditional: a river may be uncrossable on foot but crossable by bridge, ferry, or seasonal ice. Similarly, safety, security, or conservation rules may designate a region as uncrossable to prevent movement or to protect sensitive environments.

In everyday usage, uncrossable is often interchangeable with impassable, though there can be nuance. Uncrossable can imply potential crossing under certain circumstances or with significant effort and resources, whereas impassable tends to emphasize absolute or current impracticality. The term appears in travel guidance, hazard descriptions, and fiction to convey barriers that halt progress, whether they are real, temporary, or metaphorical.

See also: insurmountable, impassable, unbridgeable, barrier.