Opa! Opa!

If you speak Korean, you already know why it’s funny that a Greek restaurant in Astoria, Queens, is called Opa! Opa!

For the uninitiated, “opa” in Korean literaly translate’s to a female’s older brother, but can also denote other relationships between an older male and a younger female, both platonic and otherwise.

Now, can someone tell me what “opa” means in Greek?