Nawrse
Heard in Mayo
The posterior or arse as it is known in Éire.
"Biddy, dat feen has a mighty nawrse on him!" Note: It is common in Mayo to replace the starting letter of some words with 'n,' some examples include: nurp (burp), nawrt (fart), nawrved (starved) etc.
My word, that chap possesses a magnificent posterior!