| Abbreviation | Definition |
|---|---|
| FWU | Flight Watch Unit |
| FWV | Fixed Wing Vehicle |
| FWV | Foreign War Veteran |
| FX | Fighter X (next generation fighter aircraft) |
| FXD | Fixed |
| FXXI | Force Twenty One |
| FXXITP | Force XXI Training Program |
| FY | Fiscal Year |
| FYBP | Fiscal Year Base Plan |
| FYDP | Five Year Defense Plan |
| FYDP | Future Years Defense Plan; Future Years Defense Program |
| FYDP | Future Years Defense Program |
| FYE | For Your Eyes |
| FYEO | For Your Eyes Only |
| FYIAP | Five Year Interoperability Assurance Plan |
| FYP | Five Year Plan |
| FYP | Future Years Program |
| FYSA | For Your Situational Awareness |
| FYTP | Five Year Test Plan |
| FYU | For Your Use |