Lewis & Short

commentātor, ōris, m. [2. commentor].

  1. I. An inventor, contriver (post-class. and rare): omnium falsorum, App. Mag. p. 321, 36: evangelii, i. e. the author, Tert. Res Carn. 33.
  2. II. An interpreter: legum, Cod. Just. 1, 17, 2, § 20; Serv. ad Verg. E. 6, 11.