Lewis Short
ēlūcesco, ĕre, 3
* V. inch. n. [eluceo], to shine forth, begin to shine (late Lat.), August. Retr. 1, 13: elucesco, παρεκφαινειν, Gloss.—Esp., to dawn: donec dies elucescat,Vulg. 2 Pet. 1, 19.—Impers.: cum jam elucesceret,Vulg. 1 Reg. 9, 26.
Charlton T. Lewis, Charles Short, A Latin Dictionary