yahualtic.

Principal English Translation: 

something round, like the moon or a shield (see Molina)

Orthographic Variants: 
yaualtic
IPAspelling: 
yɑwɑltik
Alonso de Molina: 

yaualtic. cosa redonda como luna o rodela.
Alonso de Molina, Vocabulario en lengua castellana y mexicana y mexicana y castellana, 1571, part 2, Nahuatl to Spanish, f. 31v. col. 1. Thanks to Joe Campbell for providing the transcription.

Frances Karttunen: 

YAHUALTIC something round / cosa redonda como luna o rodela (M) [(2)Tp.138,249, (2)Zp.107,231]. Z has YO for YA, while T has YE. See YAHUALOĀ.
Frances Karttunen, An Analytical Dictionary of Nahuatl (Norman: University of Oklahoma Press, 1992), 334.

Attestations from sources in English: 

iaiaoaltic = round; iaiaoaliuhqui = round (speaking of the helix of the ear) (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),113.

Hanns J. Prem puts this word in the shape category of "spirally twisted" (spiralig gedreht in German) when referring to hieroglyphs.
Matrícula de Huexotzinco (Ms. mex. 387 der Bibliothèque Nationale Paris), Graz, Austria (1974), 682.

IDIEZ morfema: 
yahualtic
IDIEZ traduc. inglés: 
a round thing.
IDIEZ def. náhuatl: 
Nouhquiya YOHUALTIC. Ce tlamantli tlen eltoc zan patlachtic huan itehtenno axcanah chihchicotic; neci quence metztli temitoc. “Ne totlayi quichiuhqui tepamitl zan yahualtic. ”
IDIEZ morfología: 
yahualli, ti1, cā.
IDIEZ gramática: 
quen.
themes: 
Celestial Phenomena
Weapons, Shields, Heraldry