ETYMOLOGY
? perhaps from bung (the buttocks, the backside [obs.]) + -us (abounding in, full of)
EXAMPLE
“…Sims, after a little unartistic squaring, lunged out awkwardly, and caught Tom on the chest with his left. Tom, who was evidently waiting to find out what his adversary could do, returned smartly on the gob, and in getting back, fell on his corybungus…”
From: Tom Sayers, Sometime Champion of England,
His Life and Pugilistic Career
By Thomas Sayers, 1866
‘Fight between Tom Sayers and George Sims, for £75, on Tuesday, the 28th of February, 1854, at Longreach’
Lexicophilia 