Principal English Translation: 

woe is...

Frances Karttunen: 

-TLAHUĒLILTIC irregular verb to be unfortunate / ser desgraciado, infeliz (S) [(1)Bf.6v, (4)Cf.59v,112v,125v,130v]. The vowel of the second syllable is not marked long in the attestations. This verb occurs only in the third person singular preterit form and takes possessive rather than subject prefixes, NOTLAHUĒLILTIC ‘woe is me.’ See TLAHUĒL-LI.
Frances Karttunen, An Analytical Dictionary of Nahuatl (Norman: University of Oklahoma Press, 1992), 269.

Horacio Carochi / English: 

-tlahuēliltic = woe is . . .
Horacio Carochi, S.J., Grammar of the Mexican language with an explanation of its adverbs (1645), translated and edited with commentary by James Lockhart, UCLA Latin American Studies Volume 89 (Stanford: Stanford University Press, UCLA Latin American Center Publications, 2001), 513.

Lockhart’s Nahuatl as Written: 

-tlahuēliltic, ōno, interjection. Woe is me. Also used in 2nd person plural, ōtotlahuēliltic. pret. of a -ti verb with tlahuēlilli,m probably meaning something hated or anhorred (and it also seems that the first i should be long), which is always in 3rd person at the same time that the noun has a 1st person possessive prefix; prefixes in other persons are quite rare. Usually preceded by ōmochīuh.
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), 236.