Green’s Dictionary of Slang

pax on —! excl.

[Lat. pax, peace, i.e. enough! leave it in peace!]

confound it! the hell with it! also as n., pax, euph. for hell.

[UK]R. Brome Jovial Crew IV i: Pax o’ your fine Thing.
[UK]Dryden Wild Gallant II i: Pax on’t!
[UK]J. Addison Drummer III i: Pax on him, what do I give him the hearing for!
[UK]Sheridan Trip to Scarborough V ii: What the pax do you mean, gentlemen?