tlahpalli.

Headword: 
tlahpalli.
Principal English Translation: 

force, strength, energy (note the glottal stop after the first a, which sets it apart in meaning from tlapalli, red)

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), 237.

Orthographic Variants: 
tlahpalli
IPAspelling: 
tɬɑhpɑlli
Frances Karttunen: 

TLAHPAL-LI courage, vigor, spirit, effort / esfuerzo (C). The possessed form of this, generally but not necessarily with honorific –TZIN, serves as a greeting or part of a conventional salutation. TLAHPAL-LI contrasts with –TLAPAL ‘side’ and TLAPAL-LI ‘dye.’
Frances Karttunen, An Analytical Dictionary of Nahuatl (Norman: University of Oklahoma Press, 1992), 262.

Lockhart’s Nahuatl as Written: 

īxquich notlahpal nicchīhua, to exert all one's effort, do all one can. often in 2nd person optative, in which case it can also have the sense of keeping one's spirits up. 237