adjective, flint·i·er, flint·i·est.
Examples from the Web for flintiness
It had no bitterness, no flintiness, no damaged grain in it; but all were plump and ripe, as if they had been picked.The Commercial Products of the Vegetable Kingdom|P. L. Simmonds
Some people, Sir, would have been all flintiness and granite.The Old Curiosity Shop|Charles Dickens
It was felt that his brilliancy had a solidity back of it, a quality of flintiness that would endure.The Vision Spendid|William MacLeod Raine