Aj is the written form of the initials A.J., a nickname for combinations such as Andrew James or Anthony Joseph that is now given as a name in its own right, so it means "initials A and J" rather than carrying an old etymology. Initial names like this are a distinctly American habit, familiar from sports and television. Aj has hovered around number 1900 for two decades, with a best rank of number 1743 in 2012, and ranks number 1932 in 2025.