The PCS negative particle *bal is likely related to this preposition (Arakelova 2001:25, Kogan 2015:184). There is also a possibility that *bVl(Vy) ‘without’ is ultimately connected to the PS root *bly ‘to be worn out’ (GAG § 114 r, Tropper 2000:771, Kogan 2015:184), although this is not generally accepted (Arakelova 2001:25, Pat-El 2013).
balu, balāt - without, without the consent of, apart from, in the absence of
(CAD B 70, AHw. 100)
See related forms with the suffixed -t: OA, NA balāt ‘apart from’ (CAD B 45, AHw. 101), OA, NA balāt ‘apart from’ (CAD B 45, AHw. 101), MA balut ‘without’ (CAD B 76, AHw. 101).