experiential(s = adj.all) existential - derived from experience or the experience of existence; "the rich experiential content of the teachings of the older philosophers"; "formal logicians are not concerned with existential matters"
Derived from, or pertaining to, experience. Coleridge. [1913 Webster]
"It is called empirical or experiential . . . because it is given to us by experience or observation, and not obtained as the result of inference or reasoning."