Lewis Short
(adjective) : rīdĭbundus, a, um, rideo
* Laughing (ante-class.), Plaut. Ep. 3, 3, 32; cf. Gell. 11, 15, 2 sq.; Cato, Orat. 1, Fragm. 12: ridibunda ea dicitur quae ridentem agit aut simulat, Ter. Sc. ap. Gell. 11, 15, 3.
Charlton T. Lewis, Charles Short, A Latin Dictionary