Source : WordNet®

Big Dipper
     n 1: a group of seven bright stars in the constellation Ursa
          Major [syn: {Dipper}, {Plough}, {Charles's Wain}, {Wain},
           {Wagon}]
     2: elevated railway in an amusement park (usually with sharp
        curves and steep inclines) [syn: {roller coaster}, {chute-the-chute}]