出处：按学科分类—语言、文字 中国对外翻译出版公司《汉英成语词典》第62页（222字）
比喻尚未长大，力量或势力薄弱，阅历少，例别看他是个羽毛未丰的小伙子，却已是堪称世界一流的优秀棋手。
Don’t judge him by his youth and immaturity，for you know he’s already become a first class chess player of world standard．