What's "guard down" mean?
Native speaker’s answer
Rebecca
Great question! We often use the word "guard" to indicate emotional caution, vigilance, or wariness. For example, if someone says that you have your guard up, they mean that you are cautious and don't get close to others easily. If one "lets down their guard," it means that they have stopped being vigilant or wary. The expressions most commonly used are "to have one's guard up" and "to let down one's guard." Ex: You need to let your guard down if you want to make friends. Ex: I always have my guard up with strangers. You never know what their intentions are.