H6751 צָלַל (tsaw-lal')

KJV renderings: begin to be dark, shadowing.
Strong's definition: to shade, as twilight or an opaque object
Derivation: a primitive root (identical with through the idea of hovering over (compare H6754 (צֶלֶם)));

From James Strong's public-domain dictionaries (H), JSON edition by OpenScriptures (CC-BY-SA). Every dotted-underline word in the text links here.