Delta is the fourth letter of the Greek alphabet and means simply "fourth letter"; because the capital letter is a triangle, the word also came to describe a river "delta" where a stream fans out into the sea, as in the Mississippi Delta. The actress Delta Burke and the Australian singer Delta Goodrem are its best-known bearers. In the United States Delta jumped from number 3864 in 2015 to number 1572 in 2019, its best rank, and stands at number 2337 in 2025.