The Collaborative International Dictionary
Retinic
Retinic \Re*tin"ic\, a. [Gr. ???? resin.] (Min. Chem.) Of or pertaining to resin; derived from resin; specifically, designating an acid found in certain fossil resins and hydrocarbons.
Wiktionary
retinic
a. (context mineralogy chemistry English) Of or pertaining to resin.