Raaaaa! is the sound u make when doing or beginning to say things either you should'nt or when you really can't think of anything else to say!.
It is also the sound a horse makes when being manhandled in the sexual way- Thats right.. by a man!.
'RAAAAA! *snort snort*'
'RAAAAAA!!! i got dam hot ass nookie last nite'
' Mark and Danni were raaaaaain all night!'