Common misspelling of aitch. This is the case in almost all dialects of English. See H.(noun)
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Use "haitch" in a sentence
"Ireland we say 'aitch' that is the Presbyterians do - for some reason which escapes me Catholics say 'haitch' - another argument for integrated education."
"It says youngsters are now more likely to say "haitch" than "aitch" when pronouncing the letter H."
"I first heard of the haitch pronunciation through a passing reference in P.G."