Hi jamesmck: welcome to the board!

I don't know in what context the word is being used in the US, but Brewer has two references, the first to St Chad, the patron saint of springs [now why do leaping nuns come to mind?], and the second to that character whose bald head and large nose were depicted appearing over a wall and inquiring, "Wot, no [word filled in suit the circumstances]", as a comment or protest against a shortage or shortcoming. Widely used by the forces in WW2; created in 1938 by cartoonist "Chat" (George Edward Chatterton).