ixtomahua.

Headword: 
ixtomahua.
Principal English Translation: 

to make faces like a simpleton

James Lockhart, Nahuatl as Written: Lessons in Older Written Nahuatl, with Copious Examples and Texts (Stanford: Stanford University Press and UCLA Latin American Studies, 2001), 222.

IPAspelling: 
iːʃtomɑːwɑ
Frances Karttunen: 

ĪXTOMĀHUA to get rather fat, to be silly / atochado o tonto, o cordel algo gordo o grueso (M for subtantive) ((I) Bf.7v). See ĪX-, ĪX-TLI, TOMĀHUA.
Frances Karttunen, An Analytical Dictionary of Nahuatl (Norman: University of Oklahoma Press, 1992), 122.

Lockhart’s Nahuatl as Written: 

n. Class 1: ōnīxtomāhuac. from īxtli and tomāhua, to grow fat. 222