Phonosemantic compound. 門 represents the meaning and 𢇇 represents the sound. The simplified character 关 was adapted from the cursive form of the traditional character 關. The traditional component 門 was removed for simplification.
Components
門(meaning, deleted) — The traditional component 門 was removed for simplification.
𢇇(sound, simplified) — Shorthand for the 𢇇 component in the traditional character 關.