Swiss German for hello.
Pronounced something like “Grew-EAT-sy!” (I think. Swiss German dialects are hard!), this is what people in many (but not all) German-speaking parts of Switzerland say as an all-day greeting instead of “good morning”, “good afternoon”, “good evening” and so on. It’s quite polite and formal, and comes from the German “ich grüsse sie” meaning “I greet you”.
If you’re talking to your friends and have no need for formalities, just say “Hoi!”. It means “Hey” or “Hi” and seems an awful lot easier to pronounce…!