hallmark

 
Pronunciation: /ˈhɔːlmɑːk/

noun

  • a mark stamped on articles of gold, silver, or platinum by the British assay offices, certifying their standard of purity.
  • a distinctive feature: the tiny bubbles are the hallmark of fine champagnes

verb

[with object]
  • stamp with a hallmark: he was reprimanded for not hallmarking his work
  • mark as distinctive: this attitude hallmarks many a Briton’s behaviour abroad

Origin:

early 18th century (as a noun): from Goldsmiths' Hall in London, where articles were tested and stamped with such a mark