nonreturning

Nonreturning is an English adjective meaning not returning or not intended to return. It is formed from the negating prefix non- and the present participle returning; common spellings include non-returning and the closed form nonreturning.

In travel and commerce, nonreturning is used to describe a service or product that does not include a return option. A nonreturning ticket denotes a one-way journey, and such usage contrasts with round-trip or return tickets. In logistical contexts, nonreturning can describe shipments or packaging that are not intended to be returned.

In engineering and utilities, the closely related term non-return valve (also spelled with a hyphen) is a standard noun for a valve that permits flow in one direction only; the phrase nonreturning valve is rare and generally avoided in favor of non-return valve.

In computing, the concept of a nonreturning operation is used to describe code that does not return control to the caller, such as program termination. The related term noreturn is more common in programming languages; some languages provide attributes or annotations to indicate a noreturn function.

See also: one-way ticket, non-return valve, check valve, nonrefundable, irreversible.