hallmark · noun, verb1
1721. From hall + mark, from Goldsmiths' Hall in London, the site of the assay office, official stamp of purity in gold and silver articles. The general sense of “mark of quality” first recorded 1864. Use as a verb from 1773.
Hallmark · proper noun2
The company is named after its founder, J. C. Hall, and a reference to hallmark (“official marking”).
Etymology from Wiktionary, CC BY-SA 4.0.