Is there a way to hide account in Gmail? I use two accounts​ for email, one for contacts. I see all 3 in Gmail app, but only want to see 2. Is there a way to only see my email accounts as choices?
According to Gmail support, accomplishing this without explicity removing it from device is not possible:


  To remove the Gmail account only from the Gmail App isn't possible. If
  you do not want that account to be available in the Gmail App, the
  only way to do that is to remove it from your phone's device settings.


Ref:

Gmail Help Forum: Hide/remove a Google Account ONLY within the Gmail app