two-way

from WordNet (r) 3.0 (2006)

two-way
    adj 1: supported by both sides; "a two-way treaty" [syn:
           {bipartisan}, {bipartizan}, {two-party}, {two-way}]
    2: involving two parts or elements; "a bipartite document"; "a
       two-way treaty" [syn: {bipartite}, {two-part}, {two-way}]
    3: operating or permitting operation in either of two opposite
       directions; "a two-way valve"; "two-way traffic"; "two-way
       streets"

from The Collaborative International Dictionary of English v.0.48

Two-way \Two"-way`\, a. (Pipe Fitting)
   Serving to connect at will one pipe or channel with either of
   two others; as, a two-way cock.
   [Webster 1913 Suppl.]