The word 'staunchness' is correct and can be used in written English.
It is a noun that means loyalty, steadfastness, or determination. Example: Despite facing numerous challenges and setbacks, the team's staunchness never wavered as they continued to push forward and eventually achieved their goal of winning the championship.
The TV was on and you were making a speech which included this statement: 'When they try to intimidate us, we will not be intimidated; when they seek to change our country, our way of life by these methods, we will not be changed.' I admired your staunchness at the end of what must have been a draining week.
Mr Lafontaine had plenty of party backers on both issues; but even they were repelled when he snapped that the qualities of staunchness and sense of duty which Mr Schmidt esteemed were "secondary" ones useful, perhaps, for "running concentration camps".
Shishkin's "portrait" of Russian nature expansive and rich, not subject to time and not dependent on human emotion became associated with the staunchness and power of the Russian national character and with patriotic overtones of national history.
Some of the voices — notably the senior ones, belonging to Martin Landau and Christopher Plummer — are grimly convincing, but Elijah Wood's 9 lacks the staunchness of his Frodo.
I doubt whether this was a conscious policy on the part of Broccoli and Saltzman, but it was tempting fate to put a staunch, purebred Brit in a bunch of movies that were themselves, to a surreal degree, about the staunchness of British conduct.
Against Mr. Voysey's slick defensive sophistry, the play pits Edward's clear-eyed staunchness.
These days, the staunchness of the New York union sometimes reads like defensiveness.
He gets to safety on 26 runs, he's batted out that full morning session and shown some staunchness for England.
Impossible – absurd – enchantments define fairytale as a form of storytelling, but the magic also gives expression to thought-experiments: the wicked fairy turning out to be capable of love, the Frozen princess thawed into humanity by her heroic sister's staunchness and love.
Arrayed against staunchness and escape was Herath in full flow, an unlikely Cerberus.
Her staunchness on the subject of abusive men has its limits.
