Uncle Payther, n. — Green’s Dictionary of Slang

Uncle Payther n.

[the characteristics of Uncle Payther (Peter Flynn) a character in The Plough and the Stars (1926) by Sean O’Casey]

(Irish) a whingeing complainer.

1989

J. Healy Magill Apr. n.p.: Not since Dr Connor Cruise O’Brien condemned the Labour Party as ‘poltroons’ and ‘Uncle Paythers’ and then joined the party will we have seen so great a switcheroo [BS].