Kawaakari is a mystical Japanese word that means the glow of a river or stream in darkness or dusk, or the gleaming surface of a shadowed river (Japanese 川明かり). Kawaakari can also mean the reflection of the moonlight off flowing water.
A similar word in Latin in Obumbro. To shadow over and over: to make dark with shadow, save or keep from danger.
Obumbratus amnis – a river shadowed with trees.
Cooper’s Thesaurus Linguae Romanae & Britannicae, 1578.