tzintetl.

Headword: 
tzintetl.
IPAspelling: 
tsiːntetɬ
Alonso de Molina: 

tzintetl. cimiento de pared.
Alonso de Molina, Vocabulario en lengua castellana y mexicana y mexicana y castellana, 1571, part 2, Nahuatl to Spanish, f. 152v. col. 1. Thanks to Joe Campbell for providing the transcription.

Frances Karttunen: 

TZĪNTE-TL possessed form: -TZĪNTEYŌ foundation, base, buttocks / cimiento de pared (M), nalgas (T) [(4)Tp.135,214]. T has this incorporated into a verb, the whole construction meaning ‘to spank.’ It also occurs in X referring to the contents of a pot. See TZĪN-TLI, TE-TL.
Frances Karttunen, An Analytical Dictionary of Nahuatl (Norman: University of Oklahoma Press, 1992), 313.