noun
opposition coalition party
Refers to a political party formed by a coalition of opposition groups, typically in a parliamentary context.
連立野党は次の選挙で政権奪取を目指している。
The opposition coalition party is aiming to take power in the next election.
連立与党 refers to a ruling coalition party, while 連立野党 is an opposition coalition party.
Compound of 連立 (coalition) + 野党 (opposition party).