ixmanqui. cosa llana e ygual. Alonso de Molina, Vocabulario en lengua castellana y mexicana y mexicana y castellana, 1571, part 2, Nahuatl to Spanish, f. 46r. col. 1. Thanks to Joe Campbell for providing the transcription.
Frances Karttunen:
ĪXMANQU(I) something level, even / cosa llena e igual (M), parejo, plano (T) [(1)Tp.136]. See ĪXMAN(A). Frances Karttunen, An Analytical Dictionary of Nahuatl (Norman: University of Oklahoma Press, 1992), 115.