| | c&b | | Crash and Burn |
| | c&f | | Cost & Freight |
| | C&G | | chuckle & grin |
| | C&G | | Chuckle and grin |
| | C&V | | Chapter and Verse |
| | c.a.r. | | chicken ass retard |
| | c.c.t.v. | | closed circuit television |
| | c.c.t.v. | | closed circuit TV |
| | C.E.R. | | closer economic relations |
| | c.e.t. | | Central European Time |
| | C.G.M. | | Computer Graphics Metafile |
| | C.H.T.L. | | Can't Hold Their Liquor |
| | c.h.w.h. | | cold hands warm heart |
| | c.h.w.h. | | cold hands, warm heart |
| | c.i.c.y. | | can I see you |
| | c.o.b. | | close of business |
| | c.o.d.w.a.w. | | Call of Duty: World at War |
| | c.o.p.d. | | chronic obstructive pulmonary disease |
| | C.O.T. | | Car of Tomorrow |
| | c.o.w. | | chick of the week |
| | C.P.P.P. | | Company, Position & Person Profile |
| | C.R.T.L.A. | | Can not Remember the Three-Letter Acronym |
| | c.t.m.h. | | close to my heart |
| | c.w.u.c. | | call when you can |
| | C.Y.O.T.F.S. | | Catch You On The Flip Side |
| | C/P | | Cross Post |
| | C/S | | Change of Subject |
| | c2b | | consumers to business |
| | C3I | | Command, Control, Communications, and Intelligence |
| | CAC | | Common Access Card |
|