A devil's advocate is somebody who argues the opposite side just to test the idea. Play devil's advocate, just being devil's advocate, the devil's advocate in the room.
It was a real office in the Catholic church, held by the official appointed to argue against a proposed saint, and it was abolished in 1983. Playing devil's advocate is often a way of saying something without owning it.
1phrasedevil's advocateSomeone who argues the opposite side just to test the idea.
“I agree with you, but let me play devil's advocate and argue the other side.”
devil's advocate is a role.
From Latin advocatus diaboli, the church official appointed to argue against a proposed canonisation.
Latin
advocātus diabolī — the devil’s advocate
English, today
devil's advocate
Latin advocātus diabolī (“the devil’s advocate”), a popular title given to the officer dealing with the canonization process in the 16th c.
Etymology from Wiktionary, CC BY-SA