c. 1200, "a member of the nobility," also a low rank in the peerage, from Old French baron (nominative ber) "baron, nobleman, military leader, warrior, virtuous man, lord, husband," probably from or related to Late Latin baro "man" (source of Spanish varon, Italian barone), which is of uncertain origin. It is perhaps from Celtic or from Frankish *baro "freeman, man" or another Germanic source. In England the word merged with (probably) cognate Old English beorn "nobleman."
adjectival word-forming element, variant of -al (1) with connective -i-. From Latin -ialis, in which the -i- originally was from the stem of the word being attached but later came to be felt as connective.