In Dragon language, "Dovahkiin" is a combination of the words "Dovah," meaning "dragon," and "kiin," meaning "born," or "child" which is typically translated to "Dragonborn," but it can also be translated to "Dragonchild." Dovahkiin also has a second meaning: the "Dov" in "Dovah" refers to Dragonkind as a whole, while the "ah" means "hunter." Interpreted thus, the name reads "Dragonkind Hunter Born," or "Born Hunter of Dragonkind," an appropriate description of what the Dragonborn is destined to do.
Something of further interest is that dragons use the term Dovahkiin as a proper noun to address or talk about the Dragonborn and the dragon naming convention holds that names consist of three words. When called upon by the Greybeards after killing Mirmulnir, Dov-Ah-Kiin is stressed as three separate words. This could signal that the real translation of "Dov-ah-kiin" is "Born Hunter of Dragonkind," when the traditional naming convention of dragons is held.