An Etymological Dictionary of Astronomy and Astrophysics

Not actually a star, but the planet Venus shining brightly in the east just before or at sunrise. Opposed to → evening star.

Etymology (EN): → morning; → star.

Etymology (PE): Rujâ “morning star” in Tabari, “star” in Gilaki. This word is a variant of official Pers. ruz “day,” since in Tabari and Gilaki the phoneme z is sometimes changed into j, as in rujin = rowzan “window” and jir or jer = zir “under.” Therefore it is related to rowšan “bright, clear,” rowzan “window, aperture;” foruq “light,”
afruxtan “to light, kindle;”
Mid.Pers. rôšn “light; bright, luminous,” rôc “day;” O.Pers. raucah-rocânak “window;” O.Pers. raocah- “light, luminous; daylight;”
Av. raocana- “bright, shining, radiant;”
akin to Skt. rocaná- “bright, shining,” roka- “brightness, light;” Gk. leukos “white, clear;”
L. lumen (gen. luminis) “light,” from lucere “to shine,” related to lux “light,” lucidus “clear,” luna, “moon;” Fr. lumière “light;” O.E. leoht, leht, from W.Gmc. *leukhtam (cf. O.Fris. liacht, M.Du. lucht, Ger. Licht), from PIE *leuk- “light, brightness;” → morning; → star.