Spanish records began to add Mexico to Tenochtitlan, and in those of the first provincial council, held in 1555, we find written Tenuxtitlan Mexico. Concilios Prov., i. and ii., MS. In the course of time the older and more intricate name disappeared, though the city arms always retained the symbolio nopal and stone. Clavigero, Storia Mess., i. 168; iv. 205-70; Soc. Mex. Geog.
Boletin, vii. 408-15; Veytia, Hist. Ant. Méj., ii. 157-9; Humholdt, Essai Pol., i. 146-7; Cavo, Tres Siglos, i. 2; Carbajal Espinoza, Hist. Max., i. 92-3. See also Molina, Vocabulario. A number of derivations have been given to the word Mexico, as mexitli, navel of the maguey; metl-ico, place amidst the maguey; meixco, on the maguey border; mecitli, hare; metztli, moon; amexica, or mexica, you of the anointed ones. The signification spring, or fountain, has also been applied. But most writers have contented themselves by assuming it to be identical 
Ancient Arms of the City of Mexico from a rare print. with the mexi, mexitl, or mecitl, appellation of the war god, Huitzilopochtli, to which has been added the co, an affix implying locality; hence Mexico would imply the place or settlement of Mexica, or Mexicans. This war god, Huitzilopochtli, as is well known, was the mythic leader and chief deity of the Aztecs, the dominant tribe of the Nahua nation. It was by this august personage, who was also called Mexitl, that, according to tradition, the name was given them in the twelfth century, and in these words: 'Inaxcan aocmoamotoca ynamaz te ca ye am mexica,' Henceforth bear ye not the name Azteca, but Mexica. With this command they received the distinguishing mark of a patch of gum and leathers to wear upon their forehead and ears. Bancroft's Native races, ii. 559; iii. 295-6; V. 324-5 et passim. I can offer no stronger proof as to the way in which the name was regarded at the time of the conquest, and afterwards, than by placing side by side the maps of the sixteenth century and instituting a comparison. In Apiano, Cosmographica, 1575, is a map, supposed to be a copy of one drawn by Apianus in 1520, on w Inch Themisteton is given apparently to a large lake in the middle of Mexico; Fernando Colon, in 1527, and Diego de Ribero, 1529, both give the word
