| Subject | English | Thesaurus |
| abbr., f.trade. | C.M.Si | combined marine surcharge |
| abbr., f.trade. | C.R.M | cash on receipt of merchandise |
| abbr., f.trade. | C.R.M | cash by return mail |
| abbr., f.trade. | M.E.C. | marine extension clause (insurance) |
| abbr., law | M.H.C. | Member of the House of Commons |
| abbr., f.trade. | M.T.C/I | moment to change trim one centimeter or one inch |
| abbr., law | U.C.M.J. | Uniform Code of Military Justice |