Yeoo
A roar of delight or approval, the Irish whoop. The more o's, the happier the roarer.
Heard in Cork
Also spelt Yeeooo
Dey scored in de last minute, yeooo!

Shall I translate it into posh English for you, mucker?
My, my, what a surprise. Here it is in posh English.
They scored in the final minute. Hurrah!
Questions
What does yeoo mean in Ireland?
A roar of delight or approval, the Irish whoop. The more o's, the happier the roarer.
Where in Ireland do people say yeoo?
People say yeoo in Cork.
How do you use yeoo in a sentence?
“Dey scored in de last minute, yeooo!”
Updated
Same phrase, other counties
- Cork (not in the dictionary)