Definition of argent:
"1909: The metals are gold and silver, these being termed "or" and "argent". — Arthur Charles Fox-Davies, A Complete Guide to Heraldry"
or silver-coloured; of white or silver tincture
on a coat of arms
"1889: ...when the shield is argent, it is shown in an engraving by being left plain. — Charles Norton Elvin, A Dictionary of Heraldry"