The Luganda word for slave, “omúddu”, seems to have its origins in the Arabic word for slave, “abd” (from whence “Abdallah”, “omúddu wa Allah”). Then the Luganda word for a tower—like a telecom tower, for instance—is “omunâla”. Of course this comes from the Islamic minaret—“minarah”. These are words no Luganda speaker generally thinks of as Arabic. But since the towering construction, just as the slavery, was strongly associated with Muslims, they gave it the word straight from the Arabic into the Luganda. There are others, of course. “Kitábo” for “book“, “eddîni” for “religion”, “essâla” for “a prayer”, “ekkálâmu” for “pencil”, “eñgamíya” for camel, and so on.
I am pushed to this thinking, myself, because I found that Romans is the first thing I want to write in colloquial Luganda with the new writing system. And right there, in verse one, “δουλος Χριστου”.
By the way, the diacritics you see on those Luganda words, I hope to formalise them, as I promised, and learn them enough to use them regularly and exclusively, to write Luganda more-accurately with its tones.