開
カイ, ひら.く, ひら.き, びら.き, ひら.ける, あ.く, あ.ける, はる, か, ひらき

open, unfold, unseal

JLPT4 G3 S12 F59

The relevant seal inscription form is 門 gate + 幵# (align) → *open* wide the tall doors of a gate, to an equal degree → *make/drill a hole*; *be space between*; *develop*; *begin*; *hold* (a party/meeting etc.) (← throw open the doors); *release*.

[Full Kanji Etymology List]