Green’s Dictionary of Slang

the intonations of the Irish language, also as one who speaks the language.

c.1940–5		‘Myles na gCopaleen’ Best of Myles (1968) 66: Taw shay mahogany gas-pipe.
1956		B. Behan Quare Fellow (1960) Act II: They’d have thought it was a bloody mothers’ meeting. What with you and my other bald mahogany gas pipe here.
1981		(con. 1923) P. Crosbie Your Dinner’s Poured Out! 181: In the beginning we made fun of the whole scheme: ‘Taw shay mahogany gas-pipes / Ock neel shay, taw shay muck the full hand-cart.’.
1995		Sun. Trib. (Dublin) 2 July n.p.: He rambles off into the sunset, muttering to himself ‘Sic transit gloria swanson ... té sé mahogany gaspipe ... ’tis the classical education from the Jesuits you know.’ [BS].