Holy Roman Barn Owl is used exclusively as an exclamation of shock, outrage, horror or surprise such as in the following example:
Nick: Boris has withheld food from millions of the countries poorest children!
Jon: Holy Roman barn own!! What a total shit show!
Nick: Boris has withheld food from millions of the countries poorest children!
Jon: Holy Roman barn own!! What a total shit show!
by Rathgam December 04, 2020