Definition of royal “we” in US English:

royal “we”

noun

  • The use of “we” instead of “I” by an individual person, as traditionally used by a sovereign.

    ‘I'm using the royal “we” here as I actually did all of this myself’
    • ‘Although we can't always shake the nasty habit of writing in the royal we, occasionally one of our editors decides to shake off the cloak of anonymity to write a diatribe about a topic of their choice.’
    • ‘Given his constant use of the royal "we," he seems to be campaigning for the monarchy.’