(Latin “from what comes before”) In logic, an argument that is known to be true, or false, without reference to experience; the converse of a posteriori.
Derived by logic, without observed facts.
Not derived from experience; deductive; lacking proof; arguing from general principle to expected effect.

1. Based on hypothesis or theory rather than experiment.
2. Involving deductive reasoning from a general principle to a necessary effect; not supported by fact