iCloud: Delete a contact in iCloud
You can delete a contact at any time using Contacts on iCloud.com.
WARNING: When you delete a contact, it’s deleted on every device that has iCloud Contacts turned on.
Delete a contact completely: Select the contact in the All Contacts list, press the Delete key, then click Delete.
Delete a contact from a group: Click the group on the left, select the contact, then press the Delete key.
Deleting a contact from a group removes it from that group only.
If you accidentally delete any contacts, you can use iCloud.com to restore them. For instructions, see Restore your contacts, calendars and reminders, or bookmarks.