cuappitztic.

Headword: 
cuappitztic.
Principal English Translation: 

a stiffened or stiff person, rough, harsh; or, dry tortillas; or, a person who is skinny and wiry (like a thin stick) (see Molina)

Orthographic Variants: 
quappitztic
Alonso de Molina: 

quappitztic. lo mesmo es que quappitzauhqui.
Alonso de Molina, Vocabulario en lengua castellana y mexicana y mexicana y castellana, 1571, part 2, Nahuatl to Spanish, f. 85r. col. 2. Thanks to Joe Campbell for providing the transcription.

Attestations from sources in English: 

quappitztic = harsh (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), 95.

themes: 
Appearance
Behavior, Personality