Green’s Dictionary of Slang

royal adv.

also royally

completely, comprehensively.

T.J. Henry Claude Garton 78: ‘[A]fter the battle is over we will unite to celebrate it right royally in a grand torchlight procession’.
[US]E. Genet letter 8 Nov. in Brown An American for Lafayette (1981) 110: All excited and royally glad over the returns of the election in the U. S.
[UK]Ex-Légionnaire 1384 Legion of the Lost 177: The légionnaires were getting royally drunk.
[US]J. Rechy City of Night 196: I dont give a damn how cool you think you are, youll get Caught and get Caught royal.
[US]L. Heinemann Paco’s Story (1987) 24: He knew he was fucked-up royal.
[US]C. Hiaasen Skin Tight 177: That asshole in Queens had screwed him royal.
[US]C. Hiaasen Strip Tease 181: ‘He screwed up your roach case.’ ‘Royal.’.
[US]J. McCourt ‘Vilja de Tanquay Exults’ in Queer Street 305: I was adopted [...] / So I qualified roy’l.
[US]T. Robinson Hard Bounce [ebook] ‘He was worried we were about to do something royally fucked up’.
[US]J. Jackson Pineapple Street 67: Georgiana still played her heart out and spanked him royally [at tennis].