Korean 쩔어 sounds like [tzʌləː].
It means "awesome, fantastic".
For example, when you watch Lionel Messi's play on TV , you can use this expression.
Its derivative form are 쩐다[tzʌːnda] or 쩌네[tzʌːnei].
These three expressions have the same meaning, so it is up to you which to use.
It is informal, so be careful to use these expressions when using in public situation.
