tenamaztli.

Headword: 
tenamaztli.
Principal English Translation: 

the configuration of three hearth stones for supporting pots over fire; by extensión, triplets (see Karttunen and Molina)

IPAspelling: 
tenɑmɑstɬi
Alonso de Molina: 

tenamaztin. piedras sobre que ponen la olla al fuego, o tres criaturas nacidas juntas de vn vientre.
Alonso de Molina, Vocabulario en lengua castellana y mexicana y mexicana y castellana, 1571, part 2, Nahuatl to Spanish, f. 98r. col. 2. Thanks to Joe Campbell for providing the transcription.

Frances Karttunen: 

TENAMAZ-TLI pl: -TIN ~ -MEH the configuration of three hearth stones for supporting pots over fire; by extensión, triplets / piedras sobre que ponen la olla al fuego, o tres criaturas nacidas de un vientre (M) [(1)Tp.224, (2)Zp. 120,220, (3)Xp.84]. In T and X this is metathesized to TEMANAZ-TLI. M gives only the plural form tenamaztin. See TE-TL.
Frances Karttunen, An Analytical Dictionary of Nahuatl (Norman: University of Oklahoma Press, 1992), 224.