Mayo for Sam
The cry of Mayo supporters every summer, Sam being the Sam Maguire Cup. Said with hope, year after year.
Flags out on every house from Ballina to Westport, Mayo for Sam!

Shall I translate it into posh English for you, horsebox?
Good day! I trust you are keeping well. Here it is in posh English.
Flags fly from every house from Ballina to Westport. Mayo shall lift the Sam Maguire Cup!
Questions
What does Mayo for Sam mean in Ireland?
The cry of Mayo supporters every summer, Sam being the Sam Maguire Cup. Said with hope, year after year.
How do you use Mayo for Sam in a sentence?
“Flags out on every house from Ballina to Westport, Mayo for Sam!”
Updated
On the list: Irish slang phrases