The Swahili were a people, culture, and a language on Earth from eastern Africa.
Nyota Uhura's name is Swahili for "Star Freedom". (TOS novel: Uhura's Song)
Some translations have uhura translating into "truth". (TOS novel: The Starless World)
Kwaheri was Swahili for "goodbye". Hikaru Sulu offered this to Nyota Uhura in 2294. She responded with "Kwaheri". (TOS novel: The Fearful Summons)
In 2371, Benjamin Sisko named his Bajoran lightship Baraka, after the Swahili word for "good fortune". (DS9 episode: "Explorers", CCG set: Tenth Anniversary Collection)