Green’s Dictionary of Slang

hell or high water n.

an intensely unpleasant experience; in different phrs. such as go through hell and high water, between hell and high water; occas. as excl.

[US]Everybody’s Mag. June 69/2: He’ll be one of us in spite of hell and high water.
[US] in J.F. Dobie Rainbow in Morning 92: Hell and high water!
[US]W.M. Raine Cool Customer 317: You can buy a wedding-present with it for the young lady who went through hell and high water with you.
[US](con. 1970) J.M. Del Vecchio 13th Valley (1983) 159: We got us a good all blowed ta hell en highwater.
[US]T. Willocks Green River Rising 333: You went through hell and high water, just to be with that lady of yours.

In phrases

come hell or high water (also come hell or high tide)

no matter what the circumstance.

[US]Misc. Doc. 42nd U.S. Congr. 2 Sess. House No. 22 I 33: They might fight him?but he was going there in spite of hell and high water [OED].
[US]McLure’s Mag. XVII 380: Do you, Kyle, take this woman, Loys, to have and keep track of, come hell or high water, her heirs and assigns for ever?
[US]Century XCII 619/1: For if that squaw got a sniff of things, she 'd never tell nothing, come hell or high water.
[US]Munsey’s Mag. XCIV 312/1: ‘I aim to find Penny, come hell or high water,’ announced the young man.
[US]H. McCoy They Shoot Horses, Don’t They? in Four Novels (1983) 84: If it was Number Two you had to do you had to rush because come hell or high water, you had only five minutes.
Aberdeen Jrnl. 10 Nov. 3/4: [He] delalred that the flow of American munitions to Russia, Britain and China must go on increasing ‘despite hell and high water’.
[NZ]D. Davin For the Rest of Our Lives 76: They were going to use them, too, come hell or high water.
[US]R.L. Bellem ‘Death Ends the Scene’ Hollywood Detective May 🌐 I was determined to get [the letter] come hell or high tide.
[NZ]G. Slatter Gun in My Hand 237: I was going to have that Luger come hell or high water.
[US]D. Burke Street Talk 2 189: I’m going to get a raise come hell or high water!
[US](con. 1973) C. Stella Johnny Porno 256: The mob was going to get that money back come hell or high water.
through hell or high water

to any extent, irrespective of any possible problems.

[US](con. 1940s) C. Bram Hold Tight (1990) 214: We’ll be able to tail Rice through hell and high water.