1) Glossarist 2) Medieval law 
The scholars of the 11th and 12th century legal schools in Italy, France and Germany are identified as glossators in a specific sense. They studied Roman Law based on the Digestae, the Codex of Justinian, the Authenticae (an abridged Latin translation of selected constitutions of Justinian, promulgated in Greek after the enactment of the Codex and...
• (n.) A writer of glosses or comments; a commentator.
Glos·sa'tor noun [ Late Latin See 3d Gloss .] A writer of glosses or comments; a commentator. [ R.] 'The . . . glossators of Aristotle.' Milman. 
glossator 1. Someone who writes glosses; a glossarist. 2. One of the medieval interpreters of the Roman and cannon laws.
a person who writes glosses; glossarist. · one of the medieval interpreters of the Roman and canon laws.