It was created by orientalist writers like Lovecraft as an "exotic" name and subsequently popularized in the Anglo literatisphere as a stock Arab character name. doesn't really exist in the Arabic-speaking world as an independent name, even if it's become common in western countries.
It comes from the word "abd" (عبد) in Arabic, which means servant or slave, combined with "ul" or "al" (ال), Arabic's only definitive article. "Al" can also express possession. It's often used as part of theonyms like Abdallah, meaning literally "servant of God," or like Kareem Abd-ul-Jabbar's name which means "servant of the mighty."
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I think it may be more common in western countries where Abdul has already become a known Arab name. But like no Jordanian or Egyptian person I know has ever used that for a nickname. But Moody for Mahmoud I've heard, or like Dowdy or Doody for Dawood.