| Cycas | Cycas |
| Cycas revoluta | Cycas revoluta |
| Cyclades | Cícladas |
| Cycladic art | Arte cicládico |
| Cycladic civilization | Cicládico |
| cyclamate | ciclamato |
| cyclamen | ciclamen |
| Cyclanthaceae | Cyclanthaceae |
| cycle | bicicleta |
| Cycle graph | Círculo |
| cycle path | sendero de bicicletas |
| cycle racer | ciclista |
| cycle track | sendero de bicicletas |
| cyclic | cíclico |
| Cyclic adenosine monophosphate | Adenosín monofosfato cíclico |
| Cyclic group | Grupo cíclico |
| Cyclic guanosine monophosphate | Guanosín monofosfato cíclico |
| Cyclic process | Ciclo termodinámico |
| cyclic redundancy check | comprobación de redundancia cíclica |
| cyclical | cíclico |
| Cyclin | Ciclina |
| Cyclin-dependent kinase | Kinasas dependientes de ciclinas |
| cycling | ciclismo |
| Cycling team | Equipo ciclista |
| Cycliophora | Cycliophora |
| cyclist | ciclista |
| cyclo- | ciclo- |
| Cyclo-cross | Ciclo-cross |
| cycloalkane | cicloalcano |
| cycloalkene | cicloalqueno |
| Cyclocomputer | Ciclocomputador |
| cyclogenesis | ciclogénesis |
| cyclohexane | ciclohexano |
| cyclohexanone | ciclohexanona |
| Cycloheximide | Cicloheximida |
| cyclone | ciclón |
| Cyclone Catarina | Ciclón Catarina |
| Cyclone Sidr | Ciclón Sidr |
| Cyclone Sidr kills hundreds in Bangladesh | El ciclón Sidr deja cientos de muertos en Bangladesh |
| cyclonic | ciclónico |
| Cyclonic separation | Ciclón |
| Cyclonite | RDX |
| Cyclop | Cíclope |
| Cyclop edia | Enciclopedia |
| Cyclopes | Cíclope |
| cyclophilin | ciclofilina |
| cyclopropene | ciclopropeno |
| cyclops | cíclope |
| Cyclorana | Cyclorana |
| cyclosilicate | ciclosilicato |
| cyclostyle | reproducir en ciclostilo |
| cyclotron | ciclotrón |
| Cyclotron radiation | Radiación ciclotrón |
| Cycnus | Cicno |
| Cydippe | Cídipe |
| Cydonia | Cara de Marte |
| Cydonia Mensae | Cara de Marte |
| cygnet | pollo de cisne |
| Cygninae | Cygnus |
| Cygnus | Cygnus |
| Cygnus columbianus | Cygnus columbianus |
| Cygnus Hyoga | Hyōga |
| Cygwin | Cygwin |
| CYK algorithm | Algoritmo CYK |
| cylinder | rodillo |
| Cylinder capacity | Cilindrada |
| cylinder head | culata |
| Cylinder of Nabonidus | Cilindro de Nabonido de Sippar |
| Cylinder seal | Sello cilíndrico |
| cylindric | cilindrico |
| cylindrical | cilíndrico |
| Cylindrical coordinate system | Coordenadas cilíndricas |
| cylindricity | cilindricidad |
| Cylindropuntia | Cylindropuntia |
| Cylon | Cylon |
| Cylon of Athens | Cilón |
| cymbal | platos |
| Cymbalaria | Cymbalaria |
| Cymbeline | Cimbelino |
| Cymbopogon | Cymbopogon |
| Cymbopogon citratus | Cymbopogon |
| Cymbopogon nardus | Cymbopogon nardus |
| Cymodoceaceae | Cymodoceaceae |
| cymotrichous | cimótrico |
| Cynan | Conan |
| Cynara | Cynara |
| Cyndi Lauper | Cyndi Lauper |
| Cynegils of Wessex | Cynegils de Wessex |
| Cynetes | Conios |
| cynic | cínico |
| cynical | cínico |
| cynically | cínicamente |
| cynicism | desengaño |
| Cynipoidea | Cynipoidea |
| Cynisca | Cinisca |
| cynism | cinismo |
| Cynodon | Cynodon |
| Cynodon dactylon | Cynodon dactylon |
| Cynoglossum | Cynoglossum |
| Cynoglossum officinale | Cynoglossum officinale |
| Cynognathus | Cynognathus |
| Cynosura | Cinosura |
| cynosure | foco |
| Cynosurus | Cynosurus |
| Cynthia | Cintia |
| Cynthia Rothrock | Cynthia Rothrock |
| Cyparissus | Cupressus |
| Cyperaceae | Cyperaceae |
| Cyperales | Cyperales |
