Definition of Fructuarius
Lat. In the civil law, one who had the usufruct of a thing; i.e., the use of the fruits, profits, or increase, as of land or animals. Bracton applies it to a lessee, fermor, or farmer of land, or one who held lands ad firmam, for a farm or term.
That's the definition of Fructuarius in Black's Law Dictionary 6th Edition. Courtesy of Cekhukum.com.