Akkadian

balû - to become extinguished, to come to an end (CAD B 72, AHw. 121)

Var. belû. Derived words: belû ‘extinguished’ (CAD B 94, AHw. 121).

PS
*bly - to be old, worn out (CDG 98; Kogan 2015: 184; EDA I 212)

Connection with ESA blyt ‘to be buried suggested by W. Müller (1962: 29, 1963: 307) is doubtful (CDG 98)