Principal English Translation: 

denotes an action, makes a verb into a noun; the being or doing of something (see Carochi)

Orthographic Variants: 
Horacio Carochi / English: 

-liztli = deverbal nouns of action
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: 

makes gerunds from verbs, like English words in -ing.
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: 

e.g. cochiliztli = the action or state of sleeping (cochi = to sleep)