Lewis & Short

1. jŭvĕnālis, e, adj. [juvenis], youthful, juvenile, suitable for young people (mostly poet. and post-Aug.): corpus, Verg. A. 5, 475: arma, id. ib. 2, 518; Sil. 2, 312: mihi mens juvenali ardebat amore compellare virum, Verg. A. 8, 163: fama, Plin. 33, 2, 8, § 32: ludi, a kind of games introduced by Nero, Suet. Ner. 11; cf. dies, id. Calig. 17: ludus, Liv. 1, 57, 11.
Hence, subst.: jŭvĕnālĭa, ium, n., youthful pursuits, games, Tac. A. 14, 15; 15, 33; 16, 21; Capitol. Gord. 4.
Adv.: jŭvĕnālĭ-ter, in a youthful manner, youthfully: jecit ab obliquo nitidum juvenaliter aurum, Ov. M. 10, 675; id. A. A. 3, 733; id. M. 7, 805.
Hence, rashly, improvidently, Ov. Tr. 2, 117 al.