"Variant of Konstantinos"
The name Kostantinos is commonly a male name from the "Greek" origin.
Kostantinos is a spelling variant of Konstantinos, the Greek form of the Latin name Constantinus, which comes from the Latin adjective constans, meaning steadfast or constant. The Greek form of the name is written with an n before the s, and this spelling gives the name without it. It is a romanization difference rather than a different name.
Konstantinos means "Traditional name".
The pronunciation of Kostantinos is koh-stan-TEE-nos.