dago T n. a ribbed, white cotton tank-style undershirt; a wife-beater; a boy-beater. Editorial Note: A synonym is guinea T, which, like dago T, is often perceived as derogatory or offensive. (source: Double-Tongued Dictionary)
Further reading
When a British tabloid reporter writing about a crocodile attack needed a synonym for crocodile, he went with knobbly monster, now a joking term for similarly creative ways of avoiding repetition. Juliet and Matthew Maguire, described by The...
Some college students are using the word loyalty as a synonym for monogamy. Are the meanings of these words now shifting? Plus, a biologist discovers a new species of bat, then names it after a poet he admires. Also, warm memories of how a childhood...
Found a new instance to add to definition, used as ‘obscene slang’ against a Mr.E :
“That’s what E is—a DAGO!”
He nodded like a man who gives a last tap to a nail, and I could see he considered his remark well and truly laid.
~ H.G.Wells in Tono-Bungay, 1909