Lewis & Short

sympŏsĭăcus, a, um, adj., = συμποσιακός, of or belonging to a banquet, convivial, symposiac: quaestiunculae, Gell. 6, 13 tit. (al. sympoticae).
Subst.: Sympŏ-sĭăca, ōrum, n., the writings of Plutarch entitled Symposium, Gell. 4, 11, 13; 17, 11, 6.