An Etymological Dictionary of Astronomy and Astrophysics

The quality of a material that allows light to pass through, but only diffusely, so that objects on the other side cannot be clearly distinguished. → transparent.

Etymology (EN): From L. translucent-, p.p. of translucere “to shine through,” from → trans- + lucere “to shine,” related to lux “light,” lucidus “clear,” luna, “moon;” Fr. lumière “light;” cf. Pers. ruz “day,” 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;” O.E. leoht, leht, from W.Gmc. *leukhtam (cf. O.Fris. liacht, M.Du. lucht, Ger. Licht), from PIE *leuk- “light, brightness.”

Etymology (PE): Tarâtâb, from tarâ-, → trans- + tâb present stem of tâbidan “to shine,” variants tâftan “to shine,” tafsidan “to become hot;” Mid.Pers. tâftan “to heat, burn, shine;” taftan “to become hot;” Parthian t’b “to shine;”
Av. tāp-, taf- “to warm up, heat,” tafsat “became hot,” tāpaiieiti “to create warmth;” cf. Skt. tap- “to heat, be/become hot; to spoil, injure, damage; to suffer,”
tapati “burns;” L. tepere “to be warm,” tepidus “warm;” PIE base *tep- “to be warm.”