伐
バツ, ハツ, カ, ボチ, き.る, そむ.く, う.つ

fell, strike, attack, punish

JLPT1 G7 S6 F1816

戈 here a variant of 戉# battle-ax + 人 person (→ human agency) → *cut down* an enemy with a weapon such as a battle-ax → *defeat* → (minor meaning of) *boast* (← boast of exploits).

[Full Kanji Etymology List]