| Firefox | Using Firefox |
| Firenze | Firenze |
| Firestone | Firestone Tire and Rubber Company |
| Firewall | Firewall |
| FireWire | firewire |
| Firman | Firman |
| firme | corporation |
| firme multinationale | multinational firm |
| Firmenich | Firmenich |
| Firminy | Firminy |
| Firmus | Firmus |
| firmware | firmware |
| First Bank of the United States | First Bank of the United States |
| First Capital Connect | Wagn |
| First Certificate in English | First Certificate in English |
| First Fleet | First Fleet |
| First Group | FirstGroup |
| First Impressions of Earth | First Impressions of Earth |
| First Vienna FC | First Vienna FC |
| First-class cricket | First-class cricket |
| Firth of Clyde | Firth of Clyde |
| Firth of Forth | Firth of Forth |
| Firuzabad | Firouzabad |
| fiscal | fiscal |
| fiscalité | fiscality |
| Fischach | Fischach |
| Fischbach-Göslikon | Fischbach-Göslikon |
| Fischenthal | Fischenthal |
| Fischer | Fischer |
| Fischingen | Fischingen |
| Fischland-Darss-Zingst | Fischland-Darß-Zingst |
| Fiscus | Fiscus |
| FISH | Fish |
| fish 'n' chips | fish and chips |
| fish and chips | fish and chips |
| FishBase | FishBase |
| Fisibach | Fisibach |
| Fislisbach | Fislisbach |
| fissible | fissile |
| fissile | fissile |
| Fissilité | Chink |
| fission | fission |
| Fission nucleaire | Nuclear fission |
| fission nucléaire | nuclear fission |
| Fission spontanée | Spontaneous fission |
