Easton's Bible Dictionary (1897)
A pit, a place mentioned in 2 Sam. 21:18, 19; called also Gezer, in 1 Chr. 20:4.
Smith's Bible Dictionary (1863)
(cistern), a place mentioned only in (2 Samuel 21:18,19) as the scene of two encounters between David’s warriors and the Philistines. In the parallel account in (1 Chronicles 20:4) the name is given as Gezer.
Hastings' Dictionary of the Bible (1898) & Schaff's Bible Dictionary
GOB (ditch, or cistern). 2 Sam 21:18-19.
Hitchcock's Bible Names (1869)
cistern; grasshopper