The soldiers moved cautiously, afraid the enemy might have booby-trapped the path.

booby-trapped 是动词 booby-trap 的过去分词形式。booby-trap 由 booby（傻瓜）和 trap（陷阱）组成，字面意思是"为傻瓜设置的陷阱"，指"诡雷、诱杀装置"这种伪装成普通物品的爆炸装置。booby-trapped 表示"被设置了诱杀装置的"。