To play two (or more) roles; to hold two different positions. This expression alludes to the hats of two different uniforms. The practice is ancient, and Gilbert and Sullivan made glorious fun of it in The Mikado in the person of Pooh-Bah, who holds practically every office in the town of Titipu. The term dates from the mid-nineteenth century. A 1972 issue of the Village Voice stated, “I wear two hats. Are you asking me this question as president of the Bartenders’ Union or as chairman of the ABC?”