tiacapantli.

Headword: 
tiacapantli.
Principal English Translation: 

the first born

Fr. Bernardino de Sahagún, Florentine Codex: General History of the Things of New Spain; Book 6 -- Rhetoric and Moral Philosophy, No. 14, Part 7, eds. and transl. Arthur J. O. Anderson and Charles E. Dibble (Santa Fe and Salt Lake City: School of American Research and the University of Utah, 1961), 87.

Attestations from sources in English: 

Auh ca iz tica in titeach in tiacapãtli, auh ca iz tõca in titlacoieoa, auh in titlatoqujlia; auh iz tica ompa tica on in tixocoiutl = And here standest thou who art the oldest, the firstborn; and here art thou who art the second; and thou who followest; and thou who standest, who standest there, thou who art the youngest (central Mexico, sixteenth century)
Fr. Bernardino de Sahagún, Florentine Codex: General History of the Things of New Spain; Book 6 -- Rhetoric and Moral Philosophy, No. 14, Part 7, eds. and transl. Arthur J. O. Anderson and Charles E. Dibble (Santa Fe and Salt Lake City: School of American Research and the University of Utah, 1961), 87.

Women's birth order names seem to relate from beliefs about female deities or goddesses linked to Tlazolteotl, who loved luxury and was lustful. The four sisters were Tiacapan (the oldest sister), then Teicu (the second oldest), the third was Tlaco (middle sister), and the youngest was Xoco, or "Xocutzin." Many girls bore these names. (central Mexico, sixteenth century)
Fr. Bernardino de Sahagún, Florentine Codex: General History of the Things of New Spain; Book 1 -- The Gods; No. 14, Part 2, eds. and transl. Arthur J. O. Anderson and Charles E. Dibble (Santa Fe and Salt Lake City: School of American Research and the University of Utah, 1950), 8.