Source : WordNet®

dummy up
     v 1: make a dummy of; "dummy up the books that are to be
          published" [syn: {dummy}]
     2: refuse to talk or stop talking; fall silent; "The children
        shut up when their father approached" [syn: {close up}, {clam
        up}, {shut up}, {belt up}, {button up}, {be quiet}, {keep
        mum}] [ant: {open up}]