From the same as H8430; the bottom (as depressed); only adverbially below (often with prepositional prefix underneath), in lieu of, etc.
KJV Usage: as, beneath, X flat, in (-stead), (same) place (where . . . is), room, for . . . sake, stead of, under, X unto, X when . . . was mine, whereas, [where-] fore, with.