| Acronym | Definition |
|---|
| SYN | Synthetic |
| SYN | Synthesizer |
| SYN | Synonym (file name extension) |
| SYN | Synchronization |
| SYN | Synchronous |
| SYN | Synchronize |
| SYN | Syndicate |
| SYN | Synagogue |
| SYN | Synyster Gates (guitarist) |
| SYN | Synechocystis (bacteria) |
| SYN | Synaspismos (Greek political party) |
| SYN | Synchronous Idle |
| SYN | Synonym File |
| SYN | Student Youth Network (Australia) |
| SYN | Student Youth Network, Inc. (Australia) |
| SYN | Screw Your Neighbor (game show podcast affiliated with The Awful Show) |
| SYN | South Yorkshire Newspapers |
| SYN | Synchronous Idle Mode |
| SYN | Something Yet Nothing (band) |
| SYN | Seven Year Night (band) |
| SYN | Smoke Yourself Numb |
| SYN | Sinister Yet Noble (gaming clan; World of Warcraft) |