The name Jefferson is a boy's name of English origin meaning "son of Jeffrey". Jefferson is ranked #694 on our popularity charts and is often added to lists like American Baby Names and discussed in our forums with posts like "Help- baby must go by nickname A.J.".
From the experts:
The name of the third U.S. President sounds, like Harrison and Jackson, more modern and stylish now than its root name. Used as a first name long before our surname-crazed era, Jefferson was most famously connected to the President of the Confederacy, Jefferson Davis--and is the middle name of another Prez, William Clinton.
Fictional Jeffersons include Jefferson Bricks in Dickens's Martin Chuzzlewit and Jefferson Almond in Henry James' Washington Square, the title character in the Frank Capra classic film "Mr. Smith Goes to Washington," plus others--for better and for worse-- in "Married With Children," "The Dukes of Hazzard" and "Kit Kittridge: An American Girl."
Admittedly, nickname Jeff does sound a bit dated.