noun
minister without portfolio
A cabinet minister who is not assigned a specific ministry; often handles special assignments or acts as a coordinating figure.
彼は無任所大臣として経済政策の調整を担当した。
As a minister without portfolio, he was in charge of coordinating economic policy.
国務大臣 is a broader term for any minister of state, while 無任所大臣 specifically refers to one without a specific portfolio.
Compound of 無任所 (no assigned post) and 大臣 (minister). The term is a direct translation of the English 'minister without portfolio'.