| cosignataire | cosignatory |
| cosigner | cosign |
| Cosima Wagner | Cosima Wagner |
| Cosimo Rosselli | Cosimo Rosselli |
| cosinus | cosine |
| Cosmas de Prague | Cosmas of Prague |
| Cosmas Indicopleustès | Cosmas Indicopleustes |
| Cosmati | Cosmati |
| Cosmic Background Explorer | Cosmic Background Explorer |
| Cosmic Gate | Cosmic Gate |
| Cosmide | Cosmid |
| cosmique | cosmic |
| Cosmobiologie | Cosmobiology |
| Cosmocats | ThunderCats |
| Cosmochimie | Cosmochemistry |
| cosmodicée | cosmodicy |
| cosmodrome | spaceport |
| Cosmodrome de Baïkonour | Baikonur Cosmodrome |
| Cosmodrome de Kapustin Yar | Kapustin Yar |
| Cosmodrome de Plesetsk | Plesetsk Cosmodrome |
| Cosmodrome de Svobodny | Svobodny |
| cosmogonie | cosmogony |
| cosmologie | cosmology |
| Cosmologie branaire | Brane cosmology |
| Cosmologie de Bianchi | Bianchi cosmology |
| Cosmologie de Dirac | Dirac cosmology |
| Cosmologie hierarchique | Hierarchical cosmology |
| Cosmologie hiérarchique | Hierarchical cosmology |
| Cosmologie non standard | Non-standard cosmology |
| Cosmologie observationnelle | Observational cosmology |
| Cosmologie quantique | Quantum cosmology |
| Cosmologie relativiste | Relativistic cosmology |
| Cosmologie religieuse | Religious cosmology |
| cosmonaute | cosmonaut |
| Cosmonautes fantômes | Soviet space program conspiracy accusations |
| cosmopolite | cosmopolitan |
| cosmopolitisme | cosmopolitanism |
| Cosmopterigidae | Cosmopterigidae |
| cosmos | cosmos |
| Cosmè Tura | Cosimo Tura |
| cosmétique | cosmetics |
| cosmétiques | cosmetic |
| COSO | Committee of Sponsoring Organizations of the Treadway Commission |
| Cosoleto | Cosoleto |
| Cospas-Sarsat | Cospas-Sarsat |
| cosplay | cosplay |
| cosse | pod |
| cosse de pois | pea pod |
| Cossidae | Cossidae |
| Cossonay | Cossonay |
| Cossovo | Kosovo |
| cossu | substantial |
| Costa Blanca | Costa Blanca |
| Costa Brava | Costa Brava |
| Costa Daurada | Costa Daurada |
| Costa del Azahar | Costa del Azahar |
| Costa del Sol | Costa del Sol |
| Costa di Serina | Costa di Serina |
| Costa Rica | Costa Rica |
