| circunstancia fortuita | incidental circumstance |
| circunstancia incidental | incidental circumstance |
| circunstanciado | complicated |
| circunstancial | circumstantial |
| circunstancialmente | circumstantially |
| circunstancias fuera del alcance de uno | circumstances beyond one's control |
| circunstante | bystander |
| circunvalación | belt |
| circunvención | circumvention |
| circunvenir | circumvent |
| circunvolucion | whorl |
| circunvolución | convolution |
| circón | zircon |
| Cirenaica | Cyrenaica |
| cirenaico | Cyrenian |
| Cirene | Cyrene |
| Ciriaco De Mita | Ciriaco de Mita |
| cirilización | Cyrillization |
| Cirilización del chino mandarín | Cyrillization of Chinese from pinyin |
| Cirilización del japonés | Cyrillization of Japanese |
| Cirilo | Cyril |
| Cirilo de Alejandría | Cyril of Alexandria |
| Cirilo de Jerusalén | Cyril of Jerusalem |
| Cirilo y Metodio | Saints Cyril and Methodius |
| cirio | candle |
| Ciro | Cyrus |
| Ciro el Joven | Cyrus the Younger |
| Ciro Ferrara | Ciro Ferrara |
| Ciro I | Cyrus I of Anshan |
| Ciro II el Grande | Cyrus the Great |
| Cirque du Soleil | Cirque du Soleil |
| cirro | cirrus |
| cirrocúmulo | cirrocumulus |
| cirrosis | cirrhosis |
| Cirrosis hepática | Cirrhosis |
| Cirrus uncinus | Cirrus uncinus cloud |
| Cirsium | Cirsium |
| Cirsium arvense | Cirsium arvense |
| Cirsium eriophorum | Cirsium eriophorum |
| Cirsium oleraceum | Cirsium oleraceum |
| Cirsium palustre | Cirsium palustre |
| Cirsium vulgare | Cirsium vulgare |
| Cirth | Cirth |
| ciruela | plum |
| ciruela claudia | greengage |
| ciruela damascena | damson |
| Ciruela de fraile | Plum |
| ciruela pasa | prune |
| cirugia a los pechos | breast augmentation |
| cirugia a los senos | breast augmentation |
| cirugía | operation |
| cirugía a corazón abierto | open-heart surgery |
