N Cook wrote:

Then there is back-slang taken into Polari.
eg riah for hair
Polari somehow connects Italians, bargees, actors and homosexuals but how ?
and British Romany,

Still sometimes used in the World of The Theatre ( pronounced Thee a
Torrrr) dear boy

popularised by the likes of "dell-boy" eg Kushti.
What was the one , in the 1940s ?, where you swapped first and last
syllables and added something to make a lilt


UbbiDubbi, or Verlan

Ron