The Arabic مهنىس /Mohandis/ is (I think) nominative case, literally meaning "one who knows geometry".
Maybe you need to ask a more specific question but almost all languages are affected by languages they come in contact with. Borrowings of words for things or concepts that do not naturally exist in that language are not uncommon for any language.
English is one such language which has words borrowed from many languages that include Japanese (karaoke, tycoon, soy), Turkish (kiosk, yogurt) , Ukrainian (kasha)
Hope that helps
Apparently Swahili developed from a combination of Arabic and Bantu languages... I guess that's why those who speak Arabic and/or any bantu language will often find similarities between their language and swahili... I should know, I'm a native speaker of a bantu language and though pretty green about swahili, can often infer the meanings of swahili words from my knowledge of my own language if the root of the swahili word is a bantu language :)
Swahili is a Bantu language. When the first Arabic traders came to the East African Coast - where the Swahili were settled - they started talking to them and Arabic took influence into Swahili. As the Arab traders chose Swahili as their language for trading, it was spread further. The longer the contact went on, the more Arabic came into Swahili. So with its Bantu roots and tons of Arabic (and a little other) influence, Swahili is easy to learn both for (native) Bantu speakers and people who know Arabic (or a closely related language) well.