Origin and history of provisional

late 14c., provisioun, "foresight, prudence, care;" also "a providing beforehand, action of arranging in advance" (at first often in reference to ecclesiastical appointments made before the position was vacant), from Old French provision "precaution, care" (early 14c.), from Latin provisionem (nominative provisio) "a foreseeing, foresight, preparation, prevention," noun of action from past-participle stem of providere "look ahead" (see provide).

The meaning "something provided, supply of necessary things" is attested from mid-15c.; specific sense of "supply of food" (provisions) is by c. 1600. In law, "a stipulation, a distinct clause in a statute, etc.; a rule or principle," late 15c. A provision-car (by 1864) was a railroad car with refrigeration for preserving perishable products during transportation.

suffix forming adjectives from nouns or other adjectives, "of, like, related to, pertaining to," Middle English -al, -el, from French or directly from Latin -alis (see -al (2)).