This is the 1312th most frequent Japanese word.
自動
"Automatic."
The word 自動 (automatic) is used as an adjective to describe the functionality of the door.
このドアは自動で開きます。
This door opens automatically.
Here, 自動 is part of the compound word 自動車 (automobile/car), indicating a vehicle that operates automatically.
自動車のエンジンが壊れてしまった。
The car engine broke down.
自動 (automatic) is used as a noun modifier within the compound term 自動モード (automatic mode), describing a setting that allows the machine to function automatically.