adamancy

noun

1. (uncountable, usually)The property of being adamant.

   “Knowing the stubbornness and adamancy of born-again Christians, they're more likely to write off Borhek off as "fallen," and accuse her of succumbing to the arguments of Satan.”

   “I stuck my nose in the air, realizing too late that it was a borrowed gesture – one I’d been using for years in moments of pride or adamancy – and that it properly belonged to the woman sitting opposite me.”