Jody is a diminutive form of names such as Josephine, Joseph, and Joanna, among others that begin with 'Jo'. It gained popularity through the young male protagonist in Marjorie Kinnan Rawlings' novel 'The Yearling' (1938) and its film adaptation (1946). As a feminine name, its rise may have been influenced by the similar-sounding name Judy, which was highly popular in America during the same period.