† ˌcommentariˈographerObs.rare. [f. L. commentāri-um commentary + -grapher q.v. There may have been a mod.L. commentāriographus (cf.historiographus, -grapher) as the immediate source.] A writer of commentaries. 1576Fleming Panoplie Ep. 220 C. J. Cæsar the comentariographer.