| Subject | English | French |
| nucl.pow. | fast breeder | breeder |
| nucl.pow. | fast breeder | surrégénérateur |
| nucl.pow. | fast breeder | autogénérateur |
| commun. | fast Ethernet | fast Ethernet |
| gen. | fast jenkin | chevron |
| el. | fast motion | jogging |
| el. | fast motion | accéléré |
| commun., IT | fast path | raccourci |
| environ. | fast reactor Nuclear reactor which produces more fissile material than it consumes, using fast-moving neutrons and making plutonium-239 from uranium-238, thereby increasing the reactor's efficiency | surgénérateur |
| chem., el. | fast registration | avance |
| gen. | fast-track | accéléré |
| transp. | fast train | express |
| chem. | fast yellow | E105 |
| commun., transp. | fastest means | voie la plus rapide |
| gen. | he's the fastest over 400 metres | il est le plus rapide sur 400 mètres |
| gen. | she was the fastest in the trials | elle a fait le meilleur temps aux essais |