Source : WordNet®

trip up
     v 1: detect a blunder or misstep; "The reporter tripped up the
          senator" [syn: {catch}]
     2: cause to stumble; "The questions on the test tripped him up"
        [syn: {trip}]
     3: make an error; "She slipped up and revealed the name" [syn:
        {stumble}, {slip up}]