ボウ, バク, あば.く, あば.れる
outburst, rave, fret, force, violence, cruelty, outrage
JLPT2 G5 S15 F692
The relevant bronzeware inscription form is 日 sun/day + an element combining the curled hide of an animal with the bones still attached + 廾 pair of hands → spread an animal hide and *expose* it on the ground for drying in the sun → *reveal*. The meanings *violent*, *rough* and *sudden(ly)* are either via association (← strip a hide) or are borrowings.
[Full Kanji Etymology List]