One who believes in the existence of a priori cognition in the Kantian sense of the term. See a priori.(noun)
Of or pertaining to a priori cognition, or to apriorism.
The Century Dictionary (Public Domain)
Use "apriorist" in a sentence
"Perhaps a third category is needed, apriorist-harriers."
"The man - machine was held to be a logically valid notion not because it expressed any apriorist truth about human nature, but on the strength of induction from verifiable psychophysical data."
"His statement is too apriorist to be quite trustworthy."