c.1485, "quicksilver," from M.Fr. argent, from O.Fr., from L. argentum "silver, white money," from PIE *arg-ent- (cf. Avestan erezata-, O.Pers. ardata-, Armenian arcat, O.Ir. argat, Breton arc'hant "silver"), from base *arg- "to shine, white," thus "the shining or white metal, silver" (cf. Gk. argos "white," arguron "silver;" Skt. arjuna- "white, shining," rajata- "silver," Hittite harki- "white").
Ar"gent\, n. [F. argent, fr. L. argentum, silver; akin to Gr. 'a`rgyros silver, 'argo`s, 'argh`s, white, bright, Skr. rajata white, silver, raj to shine, Ir. arg white, milk, airgiod silver, money, and L. arguere to make clear. See Argue.]1. Silver, or money. [Archaic] 2. (Fig. & Poet.) Whiteness; anything that is white. The polished argent of her breast. --Tennyson. 3. (Her.) The white color in coats of arms, intended to represent silver, or, figuratively, purity, innocence, beauty, or gentleness; -- represented in engraving by a plain white surface. --Weale.