one-way

adjective

1. moving, or allowing movement in one direction only: a one-way street.
2. valid for travel in one direction only: a one-way ticket.Compare round trip.
3. without a reciprocal feeling, responsibility, relationship, etc.: It’s a one-way friendship.
4. not intended for return to a seller, dealer, etc., for reuse; disposable: one-way bottles.

adjective

1. moving or allowing travel in one direction onlyone-way traffic
2. entailing no reciprocal obligation, action, etca one-way agreement

adj.1906, in reference to travel tickets; 1914 in reference to streets; 1940 in reference to windows, mirrors, etc.; from one + way.