momana.

Headword: 
momana.
Principal English Translation: 

to lay down; to put down; to calm down or become calm (see Lockhart in attestations); Molina explains momana as when a snake coils or water pools. He also translates tlayohuatimomana as "everything becomes dark," suggesting a kind of spreading out

Alonso de Molina: 

momana. (pret. omoman.) enroscarse la culebra, o repressarse el agua.
Alonso de Molina, Vocabulario en lengua castellana y mexicana y mexicana y castellana, 1571, part 2, Nahuatl to Spanish, f. 58v. col. 2. Thanks to Joe Campbell for providing the transcription.

Attestations from sources in English: 

ma momana in mitl in chimalli = may the arrows and shields of war be laid down (Mexico City, sixteenth century)
James Lockhart, We People Here: Nahuatl Accounts of the Conquest of Mexico, Repertorium Columbianum v. 1 (Los Angeles: UCLA Center for Medieval and Renaissance Studies, 1993), 138.

themes: 
Snakes, Serpents
Water