letter boxBrE /ˈletə bɒks/ 🔊NAmE /ˈletər bɑːks/ 🔊 noun (BrE) (NAmE ˈmail slot) a narrow opening in a door or wall through which mail is delivered （门或墙上的）信箱 (NAmE ˈmail·box) a small box near the main door of a building or by the road, which mail is delivered to （建筑物大门口或路旁的）信箱 = postbox ➡ compare pillar box
