HFFI
| Acronym | Definition |
|---|---|
| HFFI | Healthy Fast Food, Inc. (est. 2005; Henderson, NV) |
| HFFI | Historic Fredericksburg Foundation, Inc. (Virginia) |
| HFFI | High Frequency Flow Interruption |
| HFFI | Heavy Fuel Flow Improver |
| HFFI | High-Frequency Flow Interruption Ventilation |
| HFFI | High-Frequency Pneumatic Flow Interrupter |