| Abbreviation | Definition |
|---|---|
| CNP | Continue in Next Post |
| CNP | Continued Next Post |
| CNR | Certainly No Rush |
| CNY | Chinese New Year |
| CO | Check Out |
| CO | Coming Over |
| COA | Center Of Attention |
| COAT | Champion Of All Time |
| COC | Clash Of Clan |
| COH | Change Of Heart |
| COI | Chat Over IMAP |
| COMA | Come Out Of My A** |
| Compl. | Complete |
| CONGO | Congratulations |
| CONQUER | Control, Overcome, National, Queen, Understand, Empire, and Raise. |
| COOL | Constipated Overweight Old Lady |
| COOL | Cool Oozy Overweighted Loser |
| COS | Change of Subject |
| COS | Check On Site |
| COS | Confirm On Site |