lactucic,a.Chem.|lækˈtjuːsɪk| [f. as next + -ic. Cf. F. lactucique.] lactucic acid: a crystalline acid found in the juice of the Lactuca virosa. 1838T. Thomson Chem.Org. Bodies 159 Lactucic acid was discovered by Pfaff.1865–72in Watts Dict.Chem. III. 465.