tlazopilli.

Headword: 
tlazopilli.
Principal English Translation: 

"precious nobleman," denoting a nobleman of particularly high rank and illustrious birth, but also used as a term of flattery for any nobleman (p. 154); "legitimate nobleman" (p. 16)
The Tlaxcalan Actas: A Compendium of the Records of the Cabildo of Tlaxcala (1545-1627), eds. James Lockhart, Frances Berdan, and Arthur J.O. Anderson (Salt Lake City: University of Utah Press, 1986), 154.

Orthographic Variants: 
tlaçopilli
IPAspelling: 
tɬɑsohpilli
Alonso de Molina: 

tlazopilli. hijo o hija legitimos.
Alonso de Molina, Vocabulario en lengua castellana y mexicana y mexicana y castellana, 1571, part 2, Nahuatl to Spanish, f. 118v. col. 2. Thanks to Joe Campbell for providing the transcription.

Frances Karttunen: 

TLAZOHPIL-LI someone of noble, legitimate birth / hijo o hija legitimos (M), un principal (C) [(1)Cf.117v]. See TLAZOH-TLI, PIL-LI.
Frances Karttunen, An Analytical Dictionary of Nahuatl (Norman: University of Oklahoma Press, 1992), 306.

Attestations from sources in English: 

Tlaçopilli, chalchiuitl, maquiztli teuxiuitl, quetzalli tlaçotli, tlaçotitlacatl, xocoiutl, malhuiloni, tlamaluilli, chonequiztli, hatzoio, hateuhio, uel quiztica tepiltzin. = [He is like] a precious green stone, a bracelet of fine turquoise, a precious father. [He is] an esteemed noble, a youngest child—one who deserves to be treated with tenderness, with care. [ He is] a sensitive person, not unclean, not besmirched; a fortunate noble. (central Mexico, sixteenth century)
Fr. Bernardino de Sahagún, Florentine Codex: General History of the Things of New Spain; Book 10 -- The People, No. 14, Part 11, 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), 16.

plural = tlaçopipilitin

tlazopilli = precious prince (central Mexico, sixteenth century)
Thelma Sullivan, "Tlatoania and tlatocayotl in the Sahagún manuscripts," Estudios de Cultura Nahuatl 14 (1980), 225–238. See esp. p. 227.