Male Ukrainian name (Костянтин)
Kostiantyn (Ukrainian: Костянтин) is a male name of Latin origin meaning «steadfast», «constant», «unshakeable».
The name derives from Latin Constantinus, formed from the adjective constans / constantis («constant, steadfast»). It is inseparably linked with Emperor Constantine I the Great (c. 272–337), the first Christian emperor of the Roman Empire, who legalized Christianity with the Edict of Milan in 313 and moved the capital to the city that took his name — Constantinople. In the Orthodox tradition, Saint Constantine the Great is one of the most important figures. The Ukrainian form Kostiantyn is native, with characteristic vowel reduction and palatalized -iantyn (in contrast with Russian Konstantin). The name came to Kyivan Rus directly with Christianization.
From Latin Constantinus, derived from constans («steadfast, constant»), with the suffix -inus («belonging to»).
Equivalents in other languages: Constantine (English), Constantin (French, Romanian), Costantino (Italian), Constantino (Spanish, Portuguese), Konstantin (German, Russian, Serbian, Bulgarian), Konstantinos (Greek), Konstanty (Polish), Konstantýn (Czech).
Кость, Костенько, Костусь, Костюк, Костьо, Котя, Котька, Костя, Костик, Костенька, Костечка, Костюша, Костюшка, Костюня, Костюля.
| Nominative | Костянтин |
| Genitive | Костянтина |
| Dative | Костянтинові |
| Accusative | Костянтина |
| Instrumental | Костянтином |
| Locative | Костянтинові |
| Vocative | Костянтине |