1 N-COUNT （桥、房顶等上的）矮护墙，女儿墙 A parapet is a low wall along the edge of something high such as a bridge or roof. （桥、房顶等上的）矮护墙，女儿墙

2 PHRASE 冒险/避免冒险 If you say that someone puts their head above the parapet, you mean they take a risk. If you say they keep their head below the parapet, you mean they avoid taking a risk. 冒险/避免冒险 [British]