Similar meaning (insect shelter):
* Chrysalis: Specifically refers to the pupa stage of a butterfly or moth.
* Pupa: The inactive stage of an insect's life cycle, often enclosed in a cocoon or chrysalis.
* Case: A general term for a protective covering.
* Shroud: Suggests a covering that hides something, like a cocoon hiding an emerging insect.
Metaphorical:
* Shell: A protective outer layer, like a cocoon shields an insect.
* Sanctuary: A safe and secluded place, similar to the protection a cocoon provides.
* Retreat: A place of seclusion or refuge.
* Haven: A safe and peaceful place.
Other options:
* Enclosure: A space surrounded by something.
* Covering: Anything that covers or conceals something else.
* Wrap: Something that is wrapped around an object.
* Wrap-around: A protective covering that surrounds something.
The best word will depend on the specific context and the nuance you want to convey.