圭
ケイ, ケ, か, きよ, たま, よし, かど, きよし

square jewel, corner, angle, edge

JLPT1 G13 S0 F1837

A depiction of clay/earth piled high in a neat cone shape. An ancient Chinese custom was to declare sovereignty over a particular territory by hanging a proclamation over such a pile. *Imperial present of a jade object in recognition of a lord's sovereignty* is an extended meaning from this custom. The jade object itself had a square base and was pointed at top.

[Full Kanji Etymology List]