Strong's #5014: nabab (pronounced naw-bab')

a primitive root; to pierce; to be hollow, or (figuratively) foolish:--hollow, vain.

Brown-Driver-Briggs Hebrew Lexicon:

nâbab

1) (Qal) to hollow out

1a) hollowed (participle)

Part of Speech: verb

Relation: a primitive root

Usage:

This word is used 4 times:

 

Exodus 27:8: " Hollow with boards shalt thou make it: as it was showed thee in the mount, so shall they make"
Exodus 38:7: "of the altar, to bear it withal; he made the altar hollow with boards."
Job 11:12: " For vain man would be wise, though man be born like a wild ass's colt."
Jeremiah 52:21: "cubits did compass it; and the thickness thereof was four fingers: it was hollow."