hallmark的意思是特征;特點;金銀純度印記(打在金、銀、鉑制品上，表示純度、生產日期及產地);給…打金銀純度印記。
牛津詞典：
noun
1、特征；特點。
a feature or quality that is typical of sb/sth.
Police said the explosion bore all the hallmarks of a terrorist attack.
警方稱這次爆炸具有恐怖分子襲擊的所有特征。
2、金銀純度印記（打在金、銀、鉑制品上，表示純度、生產日期及產地）。
a mark put on gold, silver and platinum objects that shows the quality of the metal and gives information about when and where the object was made.
verb
[VN]?給…打金銀純度印記。
to put a hallmark on metal goods.
柯林斯詞典：
hallmark
1、N-COUNT?標誌;特征;特點。
The?hallmark?of something or someone is their most typical quality or feature.
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誌性技術。
2、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.