Puberty is the development of secondary sexual characteristics as found in most humanoid species, as well as the development of the ability to reproduce. The secondary sexual characteristics vary greatly from species to species.
When Odo began experiencing fluctuations with his morphogenic matrix in 2372, Doctor Bashir theorized that the fluctuations were the result of a normal biological process for Changelings that was similar to puberty and menopause. Odo replied that Bashir's theory was "interesting", but suggested that the doctor keep it to himself. (DS9: "Broken Link")