ortus ūs, m orior, a rising: ante ortum solis, sunrise, Cs.: ab ortu ad occasum, from east to west. solis, the east: primi sub lumina solis et ortūs, V.: rutilo ab ortu, O.: ad umbram lucis ab ortu, from morning till night, H.

—Fig., a rise, beginning, origin: tribuniciae potestatis: iuris: ab Elide ducimus ortūs, derive our origin, O.: ortūs nascentium, the birth: Cato ortu Tusculanus, by birth: fluminis ortūs, source, O.