drop/lower/let down your guard - definition and synonyms

  1. 1
    to relax and trust people, even though this means that you might let yourself be upset or do the wrong thing. If someone does not do this, you can say that their guard is up

    She was not ready to let down her guard and confide in him.

  2. 2
    to stop being careful, for example in a game or when you are being attacked

    We cannot afford to drop our guard.

See also main entry: guard