Definition of "imperiously"

Reversing the car I got the headlights on the bird sitting on the roadside fencepost to reveal a Powerful Owl imperiously staring back at us.

2005, Sean Dooley, The Big Twitch, Sydney: Allen and Unwin, page 72

Something up above was calling him imperiously[.]

1908, Kenneth Grahame, The Wind in the Willows, London: Wordsworth Classics, published 1993, page 12