N-COUNT
（某一特征的）代名词，代表人物，典型事物
Someone or something that is a byword for a particular quality is well known for having that quality.
例句
...a region that had become a byword for violence and degeneracy.
成了暴力和堕落代名词的地区
...the Rolls-Royce brand name, a byword for quality.
劳斯莱斯品牌——品质的典范