A priori and a posteriori
Both terms appear in Euclid's Elements and were popularized by Immanuel Kant's Critique of Pure Reason, an influential work in the history of philosophy. Both terms are primarily used as  to the noun "knowledge" (i.e. " knowledge").  can be used to modify other nouns such as "truth". Philosophers may use apriority, apriorist, and aprioricity as nouns referring to the quality of being .