swahili

1. a Bantu language widely used as a lingua franca in East Africa and having official status in several countries. There are probably fewer than 2 million native speakers, but it is in everyday use by over 20 million.
2. a member of a people of Zanzibar and nearby coastal regions, descendants of the original speakers of Swahili.

adjective

relating to Swahili or to its native speakers.

from Arabic sawāḥil, plural of sāḥil ‘coast’.