A Uto-Aztecan language; the language spoken by the Aztecs and many other Mexican tribes. Related languages are disturbed sporadically from the northwestern United States to Panama. Still widely spoken in the Basin of Mexico, it is the source of a number of words current in the English language, such as tomato and chocolate. It is also the source of the widely used New World term for spear thrower, atlatl. Groups speaking Nahuatl migrated into Mesoamerica from its northern frontier, Gran Chichimec.