Currently, deleting a glossary and its components will result in their permanent deletion. Therefore, when you attempt to archive a glossary, you will get a popup message asking you to confirm your intended action: Are you sure you want to archive [insert glossary name] and all its contents?
Atlan also allows you to export your glossary assets to spreadsheets and keep a record of your contextual information.
If you inadvertently archived your glossary, Atlan creates a daily backup and you could restore the backup snapshot from the previous day. This will override any other changes that were made in the instance since that time. Note that there is no way to selectively restore specific elements that have been deleted. Hence, Atlan advises caution before proceeding with any delete actions.