self-closing
adjectiveUK /ˌselfˈkləʊzɪŋ/
US /ˌselfˈkloʊzɪŋ/
Something self-closing shuts by itself without you having to do anything.
The self-closing gate swung shut behind the puppy.
OTHER MEANINGS
2. In computing, a self-closing tag is a tag that ends itself without a separate closing tag.
In HTML, the image tag is often written as a self-closing tag.
3. A self-closing device closes automatically after being opened.
The self-closing faucet stops the water by itself.
4. Able to close or shut without outside help.
The self-closing box snapped shut when she let go.