Lewis & Short

laetĭfĭcus, a, um, adj. [laetus-facio], making glad, gladdening, glad, joyful, joyous (poet.): fetus, Lucr. 1, 193; cf. vites, Enn. ap. Cic. Tusc. 1, 28, 69 (Trag. v. 193 Vahl.): gau (i. e. gaudium), id. ap. Aus. Technop. 144 (Ann. v. 451 Vahl.): tumultus, Stat. Th. 8, 261: plausus, id. ib. 12, 521.
In neutr. plur. as subst.: laetĭfĭca, ōrum, joyful news: laetifica referre alicui, Sen. Troad. 597.