A priori

1. Applied to knowledge and conceptions assumed, or presupposed, as prior to experience, in order to make experience rational or possible.
2. Characterizing that kind of reasoning which deduces consequences from definitions formed, or principles assumed, or which infers effects from causes previously known; deductive or deductively. The reverse of a posteriori.

The word meanings were obtained from OPTED(The Online Plain Text English Dictionary), which is based on “The Project Gutenberg Etext of Webster’s Unabridged Dictionary” which is in turn based on the 1913 US Webster’s Unabridged Dictionary (See Project Gutenburg), as a text file.