Parsing inflected forms may not always work as expected. If the following does not give the correct word, try Latin Words or Perseus.
* com-mĕdĭtor, āri, v. dep., to impress carefully on one’s mind, to practise, imitate: sonitus chartarum, sounds like, Lucr. 6, 112 Munro ad loc. (but Auct. Her. 3, 18, 31 B. and K. read commode notare).