This word is almost as versatile as fuck or word. It can be used in a variety of ways, including (but not limited to):
1. Expressing excitment
2. A congratulatory exclamation
1. JZ: Trevi, I got you tickets to the Phantom Planet concert on Thursday!
Trevi: Aww yeeeuh!
2. Anna: I got an A+ on my math test!
Trevi: Aww yeeeuh!!!
3. Anna: I hate daylight savings time.
Trevi: Aww yeeeuh.