| Abbreviation | Definition |
|---|---|
| JA | Joe Average |
| JA | Johnny Angel |
| JA | Joseph Andrew |
| JA | Judith Ann |
| JAC | Janet Amelia Challice |
| JACK | Just Another Contract Killer |
| JAHMILIA | Joyful Amazing Hottie Magnificent Ignorant Loyal Intelligent and Annoying |
| JAL | Janette Anita Leah |
| JAM | James Alexis Maurice |
| JAM | Joseph Adam Matthew |
| JAN | Janet |
| JAN | Janice |
| JAP | Jose Antonio Paulo |
| JAS | James |
| javi | Javier |
| JAX | James Allen Xavier |
| JB | Jackson Browne |
| JB | Jarrods Boy |
| JB | Jeremy's Babe |
| JB | Jerry Brian |