Where does “自動扉” come from?

自動扉 (Japanese) comes from Japanese 自動, from Japanese 自動詞, from Japanese 詞, from Middle Chinese 詞.

Ancestry of “自動扉”, step by step

自動扉 traces back through two separate lines of ancestry.

via Japanese 自動

StepLanguageWordMeaning
1Japanese自動automatic movement, automatic functioning;...
2Japanese自動詞intransitive verb
3Japanese詞word; word; part of speech
4Middle Chinese詞—

via Japanese 扉

StepLanguageWordMeaning
1Japanese扉a door
2Japanese戸door; a plate placed on doorway; houses;...
3Middle Chinese戶—
Every word from Middle Chinese 詞 →Every word from Japanese 自動 →Every word from Japanese 自動詞 →