Green’s Dictionary of Slang

how the devil...? phr.

[devil, the phr. (1)]

a general interrog. intensifier; a var. on what the devil...? phr.

[UK]R. Brome Covent-Garden Weeded II ii: How the devil got they acquainted?
[UK]Wycherley Plain-Dealer I i: But how the devil cou’d you turn a man of his Quality down Stairs?
[UK]J. Dalton Narrative of Street-Robberies 47: How the D---l in the Name of G-d dare you commit such a Crime in my House.
[UK]Thackeray Yellowplush Papers Works III (1898) 253: How the d-dd – the deddy – deddy – devil – could he have seen me twice?
[UK]M. Williams Round London 26: How the -- did you get in that state?
[UK]E.W. Hornung Black Mask (1992) 206: How the devil was I to find out?
[UK]E. Raymond Tell England (1965) 51: How the devil are you?
[UK]‘Sapper’ Third Round 641: How the devil can you prove anything?
[US]M. Spillane One Lonely Night 49: I wish I knew how the devil he spotted us.