nenca.

Headword: 
nenca.
Principal English Translation: 

1) to be idle, without profit; in vain, futile (see Karttunen); 2) to have lived (see attestations in English)

Orthographic Variants: 
nēncah
IPAspelling: 
neːnkɑh
Alonso de Molina: 

nenca. ni. (pret. oninencatca.) estar ocioso y sin alguna ocupacion.
Alonso de Molina, Vocabulario en lengua castellana y mexicana y mexicana y castellana, 1571, part 2, Nahuatl to Spanish, f. 67v. col. 2. Thanks to Joe Campbell for providing the transcription.

Frances Karttunen: 

NĒNCAH to be idle, without profit, in vain, futile / estar ocioso y sin alguna ocupación (M) [(2)Tp.167,221,(4)Zp.18,64,127,177]. T and Z both have this in composition with ZAN, either before or after NĒNCAH, the phrase functioning adverbially. See NĒN, the verb CĀ.
Frances Karttunen, An Analytical Dictionary of Nahuatl (Norman: University of Oklahoma Press, 1992), 166–167.

Attestations from sources in English: 

"nenque...as Karttunen points out, this adverbial contrasts phonemically with the preterit form of the verb nemi 'to live,' which is nen-, only by vowel length, which is not marked in this manuscript. Since in all four occurrences nenca is the only verb option in the phrase and clearly is not functioning adverbially, the more valid contextual choice must be 'they lived.'"
Willard Gingerich, "TLAMACHILIZTLAHTOLÇAÇANILLI: A Performance Translation of the Náhuatl 'Wisdom-Discourse Fables' from the Manuscript of 1558," MSU Digital Commons, 2022, 32.

Attestations from sources in Spanish: 

notecitzin ytoca Ana Necaciuatl = mi madre [sic pro: cuñada], llamada Ana Nencasiguatl (Santa Bárbara)
Vidas y bienes olvidados: Testamentos indígenas novohispanos, vol. 1, Testamentos en castellano del siglo XVI y en náhuatl y castellano de Ocotelulco de los siglos XVI y XVII, eds. Teresa Rojas Rabiela, Elsa Leticia Rea López, y Constantino Medina Lima (Mexico: CIESAS, 1999), 242–243.