It's a frequent problem that many Arabs refer to the spoken dialects of the language — the language they learned at their mother's knee — as "slang," when speaking to English-speakers; of course substantial numbers of Arabs do not even know the literary language. But even if we tolerate equating "slang" and the colloquial dialects (which I emphatically don't), most of the reporting on the Ayrault name transliteration problem still gets it wrong. That story went viral (not due to my posting it, alas) and a great many of the reports were similar to this one at CNN: "The prime minister's last name, it turns out, sounds like an Arabic slang word for penis."
True, others said that it was a case of having that meaning in certain dialects, which is technically true since only in some dialects is أيره pronounced like Ayrault's name, with an "o" vowel. But the word itself, is a perfectly good literary Arabic word with the same meaning, it's just pronounced ayruhu instead of ayro. But either way, it's still spelled أيره . And the whole story centers around what it looks like on the printed page.
It appears in the classical dictionaries such as the Lisan al-‘Arab.and, below, in Lane's great multi-volume Arabic-English Lexicon. It's true that he defines several of its forms using Latin, but hey, he was writing in the Victoran era. And, "compressed?"
This is, I hope, my last word on this subject.