The hallmark of something or someone is their most typical quality or feature.
例句
It's a technique that has become the hallmark of Amber Films...這已經成為安伯電影公司的標志性技術。The killing had the hallmarks of a professional assassination...這起謀殺案具有職業暗殺的特征。
N-COUNT
（金、銀、鉑制品上標明純度、產地、制造者的）印記
A hallmark is an official mark put on things made of gold, silver, or platinum that indicates the quality of the metal, where the object was made, and who made it.
英漢詞典釋義
n.
(金銀制品上的)純度印記
The silver vase had been hallmarked at Birmingham.這個銀瓶是在伯明翰打上純度標記的。
特點,特征,標志
The burglary had all the hallmarks of a professional job.從各方面來看,這起入室行竊案都是職業慣犯做的。Clear expression is the hallmark of good writing.表達清楚是好文章的特點。One hallmark of a good politician is his ability to influence people.衡量一個優秀政治家的標志之一就是他影響大眾的能力。
英英詞典釋義
Noun
1. a distinctive characteristic or attribute
2. a mark on an article of trade to indicate its origin and authenticity