柯林斯词典life jacket (also lifejacket) (life jackets) 1. N-COUNT A life jacket is a sleeveless jacket which helps you to float when you have fallen into deep water. 救生衣 返回 life jacket剑桥词典a piece of equipment , like a jacket without sleeves , that is filled with air or light material and is designed to help you float if you fall into water 救生衣,救生背心 也見life preserver 返回 life jacket