This rare kanji has no clear standalone meaning. Treat its meaning as uncertain.
劰 combines 白 (white) and 力 (power/strength). The exact historical development is uncertain, and it is a rare character with no widely established etymology.
Since the meaning is unclear, picture a white 白 force 力: perhaps a blank, powerful energy with no defined purpose.
For バク, imagine a white 白 bull 力 charging backward: back -> バク, and the bull's white force is unstoppable.