tlaneci.

Headword: 
tlaneci.
Principal English Translation: 

for day to break, for it to get light; to get clarity (see Karttunen and Molina)

IPAspelling: 
tɬɑneːsi
Alonso de Molina: 

tlaneci. (pret. otlanez.) hazer claridad o amanecer.
Alonso de Molina, Vocabulario en lengua castellana y mexicana y mexicana y castellana, 1571, part 2, Nahuatl to Spanish, f. 127v. col. 2. Thanks to Joe Campbell for providing the transcription.

Frances Karttunen: 

TLANĒC(I) pret: TLANĒZ for day to break, to get light / hacer claridad o amanecer (M) [(5)Cf.36v,79r, (2)Zp.9,211]. See NĒC(I).
Frances Karttunen, An Analytical Dictionary of Nahuatl (Norman: University of Oklahoma Press, 1992), 284.

Attestations from sources in English: 

tlaneci (verb) = to dawn, to become day; ye tlaneci = the day breaks
Daniel Garrison Brinton, Ancient Nahuatl Poetry: Containing the Nahuatl Text of XXVII Ancient Mexican Poems (1877), 165.

tlanēci = things appear, i.e. the day is dawning
Michel Launey, An Introduction to Classical Nahuatl, translated and adapted by Christopher MacKay (Cambridge: Cambridge University Press, 2011), 141.

themes: 
Time, Calendar, Frequency