| Cybride | Cybrid |
| Cybèle | Cybele |
| Cycadaceae | Cycas |
| Cycas | Cycas |
| Cycas circinalis | Cycas circinalis |
| Cycas du Japon | Cycas revoluta |
| Cyclades | Cyclades |
| cyclamate | cyclamate |
| cyclamen | cyclamen |
| cyclane | cycloalkane |
| Cyclanthaceae | Cyclanthaceae |
| cycle | cycle |
| cycle biogéochimique | biogeochemical cycle |
| cycle biologique | biological cycle |
| Cycle carbone-azote-oxygène | CNO cycle |
| Cycle cellulaire | Cell cycle |
| Cycle CNO | CNO cycle |
| Cycle combiné | Combined cycle |
| Cycle de Beau de Rochas | Four-stroke cycle |
| Cycle de Calvin | Calvin cycle |
| Cycle de Carnot | Carnot heat engine |
| Cycle de Doha | Doha Development Round |
| Cycle de développement | Software development process |
| Cycle de Fondation | The Foundation Series |
| Cycle de Francis Sandow | Isle of the Dead |
| Cycle de Krebs | Citric acid cycle |
| cycle de l'azote | nitrogen cycle |
| cycle de l'eau | hydrologic cycle |
| Cycle de la Compagnie noire | The Black Company |
| cycle de la vie | life cycle |
| Cycle de Majipoor | Majipoor series |
| Cycle de Tschaï | Planet of Adventure |
| cycle de vie d'un produit | product life cycle |
| cycle de vie des matériaux | material life cycle |
| cycle des substances nutritives | nutrient cycle |
| Cycle des taches solaires | Sunspot cycle |
| Cycle du carbone | Carbon cycle |
| Cycle du combustible nucléaire | Nuclear fuel cycle |
| Cycle du glyoxylate | Glyoxylate cycle |
| Cycle du phosphore | Phosphorus cycle |
| Cycle du soufre | Sulfur cycle |
| Cycle en V | V-Model |
| Cycle Kondratieff | Kondratiev wave |
| Cycle limite | Limit-cycle |
| Cycle menstruel | Menstrual cycle |
| Cycle metonique | Metonic cycle |
| Cycle métonique | Metonic cycle |
| Cycle proton proton | Proton proton cycle |
| Cycle sexagésimal | Sexagenary cycle |
| Cycle sexagésimal chinois | Sexagenary cycle |
| Cycle sexuel | Sexual cycle |
| Cycle solaire | Facula |
| Cycle soufre-iode | Sulfur-iodine cycle |
| Cycle thébain | Theban Cycle |
| Cycle troyen | Epic Cycle |
| cycle à quatre temps | four-stroke engine |
| cycle œstral | estrus |
| Cyclines | Cyclin |
| cyclique | recurrent |
| cycliser | cyclize |
| cyclisme | cycling |
| Cyclisme artistique | Artistic cycling |
| Cyclisme aux Jeux Olympiques | Cycling at the Summer Olympics |
| Cyclisme de descente | Downhill cycling |
| Cyclisme handisport | Handcycle |
| cyclisme sur piste | track cycling |
| Cyclisme sur route | Road bicycle racing |
| Cyclisme urbain | Utility cycling |
