One who had attained his full rights as a citizen

There are three meanings to this word: a man who was free of trade taxes and who shared in the profits of the borough in which he lived and traded, a tenant who was free of feudal service and a man who had served his apprenticeship and who could then work at his trade in his own right. In the city of London nearly all freemen became so by virtue of being freemen of a City Guild. On attaining company freedom, a man would automatically apply for the freedom of the City. He was entitled to call himself ‘Citizen’ and, (for example), ‘Tallow Chandler’. (Dict Gen Fitzhugh). 574. 578.

those of free status in the eyes of the law, i.e., not villeins.