Come Hell or __; No Matter What Difficulties Occur

This page is the CodyCross answer for the clue below from London, Group 489, Puzzle 5 (Margaret Thatcher).

Question is: Come Hell or __; No Matter What Difficulties Occur

and the answer is: HIGHWATER

Word Meaning:

HIGH WATER — (uncountable) The location of high tide on a coastal area.

Definitions from Wiktionary.