How do I remove an alias from my Apple ID?
How do I remove an xxx@icloud.com alias from my Apple ID?
iPhone 7 Plus, iOS 10.3.3
How do I remove an xxx@icloud.com alias from my Apple ID?
iPhone 7 Plus, iOS 10.3.3
From your question I assume you already have an @me.com address (which is automatically an Apple ID) - is this correct? When iCloud was introduced @me.com (and @mac.com for those who have them) accounts had @icloud.com addresses added to the account (all having the same text before the '@'). All three are effectively the same address and you cannot delete one of them.
If the problem is that, while you are using the @me.com address, you are getting spam to the @icloud.com address, you can handle this by setting up a Rule on the iCloud website to move all incoming messages addressed to the @icloud.com address to the Trash, from where it will be automatically deleted after a week. (Go to the Mail page at icloud.com, click the cogwheel icon at bottom left, and choose 'Rules').
Your Apple ID enables you to sign into the iTunes Store, make purchases of hardware in the online Store, and create and sign into an iCloud account. Your iCloud account includes facilities for syncing data and for storing backups and photos, and you sign into it with your Apple ID.
When you created the iCloud account and enabled Mail in it, you were asked to create an @icloud.com address. This address is not your Apple ID. Once created it cannot be changed (other than by closing the account and opening an entirely new one - which would of course not contain the data in the first account). You can add up to three additional addresses (not accounts) in the form of 'email aliases' which deliver into the inbox alongside the main address: you can give out one of these addresses to people and ignore the main @icloud.com address.
You should be aware before you start that once you've created an alias you cannot turn that address into a full iCloud account or move it to another account.
More information on aliases here: http://help.apple.com/icloud/#mm6b1a490a
How do I remove an alias from my Apple ID?