崩
ホウ, くず.れる, くず.れ, くず.す

crumble, die, demolish, level

JLPT1 G7 S11 F778

As per 朋# (spread in alignment) + 山 mountain → dirt spreading in alignment as a hill/mound collapses (compare 壞, 隨 and 圮) → *collapse*; *crumble*; *fall apart*; *break*; *destruction*; *demolition* → *decline*; *worsen*; *rout* (an enemy position).

[Full Kanji Etymology List]