*use·ful/`jusfəl; ˈjuːsfəl/ adj something that is useful makes it easier for you to do something or get something 有用的，有帮助的: a useful book for travellers 对游客有帮助的书 come in useful (=be useful and help you to do something) 派上用场: His knowledge of Italian was to come in useful later on. 他学的意大利语后来派上了用场。