Full Idea
A priori is supposed to mean something which can be known independently of experience, …but possible for whom? God, or the Martians? …Instead of 'a priori truth' it is best to stick to whether some person knows it based on a priori evidence.
Gist of Idea
Rather than 'a priori truth', it is best to stick to whether some person knows it on a priori evidence
Source
Saul A. Kripke (Naming and Necessity lectures [1970], Lecture 1)
Book Reference
Kripke,Saul: 'Naming and Necessity' [Blackwell 1980], p.34
A Reaction
[compressed] This is Kripke's famous attempt to establish that 'a priori' is strictly an epistemological term, and should not be taken as a term of metaphysics (or modal semantics?). I definitely prefer the Kripke view, though it downgrades the a priori.