peradventure

My general take is my son’s father-in-law is pretty much sanctimonious beyond all peradventure.

“It is beyond peradventure that Central Valley Meat is responsible for the significant increase in COVID-19 cases in Kings county,” the lawsuit states.

“The Court has made that clear beyond peradventure.”

For example it's much more useful to know the word "house" than the word "abode," and you'll get fewer odd looks if you say "perhaps" rather than "peradventure".

“Sirs, while I would liefer commend the nobility of restraint, here must I endorse rather the vigor of lively opposition, lest, peradventure, we find that inaction is in itself the occasion of profligacy.”