self-shutting
adjectiveUK /ˌselfˈʃʌtɪŋ/
US /ˌselfˈʃʌtɪŋ/
Closing by itself without a person doing it.
The self-shutting gate swung closed behind the puppy.
OTHER MEANINGS
2. Able to close on its own after being opened.
The self-shutting drawer slid back into place.
3. Designed to shut automatically for safety or convenience.
The self-shutting lid kept the cookies fresh.
4. Closing itself as part of a machine or device.
The self-shutting box snapped shut when the toy was put away.