Bipartisan is what news people say when two political parties work together, especially two that usually fight. In US English this almost always means Democrats and Republicans both backing the same law or committee. The word sounds warm, like “everybody agreed,” but it still usually leaves out smaller parties, independents, and people who vote for no one. You hear it in newspapers, TV, and speeches — not around the dinner table. Writers sometimes stretch it to mean “both sides in a fight,” even when those sides are not parties at all; that is looser than the careful sense. In Taiwan, English news uses it a lot about America; for our own politics, people more often say the Chinese.