Strong's #6751: tsalal (pronounced tsaw-lal')

a primitive root (identical with 6749 through the idea of hovering over (compare 6754)); to shade, as twilight or an opaque object:--begin to be dark, shadowing.

Brown-Driver-Briggs Hebrew Lexicon:

tsâlal

1) to be or become or grow dark

1a) (Qal) to become or grow dark

1b) (Hiphil) to shadow

Part of Speech: verb

Relation: a primitive root [identical with H6749 through the idea of hovering over (compare H6754)]

Usage:

This word is used 2 times:

 

Nehemiah 13:19: "that when the gates of Jerusalem began to be dark before the sabbath, I commanded that the gates"
Ezekiel 31:3: "in Lebanon with fair branches, and with a shadowing shroud, and of a high stature; and his top"