φρέαρ a hole in the ground (dug for obtaining or holding water or other purposes), i.e. a cistern or well; figuratively, an abyss (as a prison)Derivation: of uncertain derivation;KJV Usage: well, pit.
Thayer:1) a well 2) the pit of the abyss (because the nether world is thought to increase in size the further it extends from the surface of the earth and so resemble a cistern, the orifice of which is narrow)
φρέαρ phrear freh'-ar Of uncertain derivation; a hole in the ground (dug for obtaining or holding water or other purposes), that is, a cistern or well; figuratively an abyss (as a prison)KJV Usage: well, pit.