Latin is an ancient Human language that originated on ancient Earth, in Europe, first spoken by humans in the regions surrounding Rome. Latin was the official language of the Roman Empire, and influenced later human languages, including English. Languages which evolved directly from Latin - such as French, Spanish, Italian - are referred to as Romance languages.
Even though the language was no longer in everyday use by the 24th century, Latin was still quite influential, and a course on Latin was offered at Starfleet Academy. Wesley Crusher took this course, and was able to tell Captain Jean-Luc Picard that his Latin was better than before. (TNG episode: "The Game")
- Ex astris, scientia is Latin for, "From the stars, knowledge".
- Cogito, ergo sum is Latin for, "I think, therefore, I am." (TNG episode: "Ship in a Bottle")
- Inter Arma Enim Silent Leges is Latin for, "In time of war, the law falls silent." (DS9 episode: "Inter Arma Enim Silent Leges")
- Sic transit gloria mundi is Latin for, "Thus passes the glory of this world." (TOS - Mirror Universe novel: The Sorrows of Empire)