Antonyms of adj four-party

1 sense of four-party

Sense 1
quadripartite, four-party -- (involving four parties)

INDIRECT (VIA multilateral) -> unilateral, one-sided -- (involving only one part or side; "unilateral paralysis"; "a unilateral decision")

Similarity of adj four-party

1 sense of four-party

Sense 1
quadripartite, four-party -- (involving four parties)
       => multilateral (vs. unilateral), many-sided -- (having many parts or sides)