two–way

1 :  moving or allowing movement in either direction a two–way bridge

2a :  involving or allowing an exchange between two individuals or groups there must be good two–way communication — Jerrold Orne; especially :  designed for both sending and receiving messages two–way radiob :  involving mutual responsibility or reciprocal relationships political alliance is a two–way thing — T. H. White †1986

3 :  involving two participants a two–way race

4 :  usable in either of two manners a two–way lamp

5 :  being a cock or valve that will connect a pipe or channel with either of two others