The Collaborative International Dictionary of English v.0.48:

Argentic \Ar*gen"tic\, a. (Chem.)
   Pertaining to, derived from, or containing, silver; -- said
   of certain compounds of silver in which this metal has its
   lowest proportion; as, argentic chloride.
   [1913 Webster]

WordNet (r) 3.0 (2006):

argentic
    adj 1: relating to compounds in which silver is bivalent