Yanni actually mean "kind of" when used in Arabic. The reason why Westerners find this funny is as follows:
Yanni is a Greek, mullet-haired, uber-performer musician, famous for two things, his relationship with Dynasty's Linda Evans who played Krystle Carrington and for his composition, Aria, which was used to advertise British Airways in the 1990s. Why do I tell you this? Because when someone whose mother tongue is Arabic speaks English, and is at a loss for a word, you'll hear "yaaaaani". Yaani is actually translated to "means" but can also mean "er" or "um", or used in a similar way to when a teenage, usually American, female says "like" - "You know, like, when, like, there was this one time, er" Replace all offending words with "yanni" and you get the picture. Listen out for it, yanni.