Presumed without analysis.
Self-evident, intuitively obvious.
Based on hypothesis and theory rather than experiment or empirical evidence.
Developed entirely from scratch, without deriving it from existing languages.
In a way based on theoretical deduction rather than empirical observation.
Pertaining to or based on experience (often, in contrast with having a basis in theoretical explanation).
Pertaining to, derived from, or testable by observations made using the physical senses or using instruments which extend the senses.
Verifiable by means of scientific experimentation.