noun
grand coalition; grand alliance
Political term for a coalition government formed by multiple major parties, often in a parliamentary system.
大連立が成立すれば、政策の安定が期待される。
If a grand coalition is formed, policy stability is expected.
連立政権 is a general term for any coalition government, while 大連立 specifically refers to a grand coalition involving major parties that are normally rivals.
Compound of 大 (dai, 'big, grand') and 連立 (renritsu, 'coalition, alliance'). The term is a modern political expression.