You can delete POS Items/Groups, which will flag them as inactive and hide them from use in the CivicRec Catalog. This will not affect past transactions and receipts.
The only way to restore deleted/archived POS items is via a Support request.
- Navigate to POS Items
- Select the category that the item you would like to remove is under
- Select the red X next to the item you want to remove
- Select OK on the Delete this POS item? pop-up window