
noun
- an automobile passenger who offers the driver unsolicited advice, warnings, criticism, etc., especially from the backseat.
- any person who, by means of criticism, unsolicited advice, or the like, interferes in affairs that are not his or her concern or responsibility.
noun informal
- a passenger in a car who offers unwanted advice to the driver
- a person who offers advice on or tries to direct matters that are not his or her concern
A passenger who gives unwanted and/or unneeded directions to the driver; also, a person who interferes in affairs without having knowledge, responsibility, or authority for doing so. For example, Aunt Mary drives us all crazy with her instructions; she’s an incurable backseat driver. This term originated in the United States in the 1920s, when it was first used for a passenger legitimately directing a chauffeur, and it was quickly transferred to figurative use. Also see the synonym Monday-morning quarterback and the antonym take a back seat.