come off it

Quit pretending or acting foolish or lying. Originally Ameri- can slang dating from about 1900, it may, as one writer suggests, be related to coming down from a high perch or position of lofty pompousness (see ON ONE’S HIGH HORSE). W. Somerset Maugham, a master of realistic dialogue, wrote, “Come off it, Roy . . . I’m too old a bird to be caught with chaff ” (Cakes and Ale, 1930).