Principal English Translation: 

causative ending for verbs; meaning to make (something) happen

Horacio Carochi / English: 

-ltia = causative ending of verbs
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), 505.

Lockhart’s Nahuatl as Written: 

Class 3: -ltih.
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), 223.

Attestations from sources in English: 

"In a number of verbs, an irregular causative in -ltia is used along with the one in -tia to form the honorific:
Mohuetzītia or Mohuetziltia = He falls.
Màxītia or Màxiltia = He arrives."
Michel Launey, An Introduction to Classical Nahuatl, translated and adapted by Christopher MacKay (Cambridge: Cambridge University Press, 2011), 215.