teicu.

Headword: 
teicu.
Principal English Translation: 

younger sister (see Molina); also seen as a personal name

Orthographic Variants: 
teicuh, Teicuhton, Deycuihto
Alonso de Molina: 

teicu. hermana menor.
Alonso de Molina, Vocabulario en lengua castellana y mexicana y mexicana y castellana, 1571, part 2, Nahuatl to Spanish, f. 94v. col. 1. Thanks to Joe Campbell for providing the transcription.

Attestations from sources in English: 

ytoca deycuihto = named Teicuhton (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), 122–123.

ytoca tecuic = named Teicuh (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), 116–117.

Women's birth order names seem to relate from beliefs about female deities or goddesses linked to Tlazolteotl (also known as Ixcuina), 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.