xocoyotl.

Headword: 
xocoyotl.
Principal English Translation: 

the youngest child, the last child, whether son or daughter (see Molina and Karttunen); also, a personal name for a woman

IPAspelling: 
ʃoːkoyoːtɬ
Alonso de Molina: 

xocoyotl. hijo o hija menor o postrera.
Alonso de Molina, Vocabulario en lengua castellana y mexicana y mexicana y castellana, 1571, part 2, Nahuatl to Spanish, f. 160v. col. 1. Thanks to Joe Campbell for providing the transcription.

Frances Karttunen: 

XŌCOYŌ-TL pl: -MEH youngest child / hijo o hija menor o postrera (M) This frequently occurs as a possessed plural, NOXŌCOYŌHUĀNE ‘my children’ (vocative) meaning literally ‘my youngest children.’ See XŌCOH.
Frances Karttunen, An Analytical Dictionary of Nahuatl (Norman: University of Oklahoma Press, 1992), 330.

Lockhart’s Nahuatl as Written: 

youngest child; with dynastic names, the Younger. in the possessed form and vocative, a polite or affectionate form of address. xōcoh youngest child, -yōtl.
James Lockhart, Nahuatl as Written: Lessons in Older Written Nahuatl, with Copious Examples and Texts (Stanford: Stanford University Press and UCLA Latin American Studies, 2001), 241.

Attestations from sources in English: 

yn quimotatia tlacatl nocoltzin moyetzticatca Señor don Pº motecuhçoma yn iuh quitohua ca yxocoyouh yetiuh Auh ynin ca ye nocontepotztoquiliz auh ca ye mopinauhtiz = my late sir grandfather señor don Pedro Motecuhçoma, as he says that he will be his youngest son. As to this, I will inquire into it and he will surely come to shame
(Mexico City, 1587)
Beyond the Codices, eds. Arthur J.O. Anderson, Frances Berdan, and James Lockhart (Los Angeles: UCLA Latin American Center, 1976), Doc. 32, 202–203.

xoco = Youngest Sister, a name for girls (Central Mexico, sixteenth century)
Fray Bernardino de Sahagún, Primeros Memoriales, ed. Thelma D. Sullivan, et al. (Norman: University of Oklahoma Press, 1997), 254.

ytoca xocoyotl = named Xocoyotl (Cuernavaca region, ca. 1540s)
The Book of Tributes: Early Sixteenth-Century Nahuatl Censuses from Morelos, ed. and transl. S. L. Cline, (Los Angeles: UCLA Latin American Center Publications, 1993), 112–113. Also seen in at least another household, 120–121.

Xocoyotl was a common name in what is now the Mexican state of Morelos. (see Carrasco)

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.

in cioatzintli, in at amotlacoieoauh, in at amotiacapan, in at noҫo amoxocoiouh = the little woman who is perhaps your second child, perhaps your eldest, or perhaps your 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), 153.

themes: 
Children, Childhood, Adolescence
Family, Kinship, Descent
Women, Men, Gender