achitonca.

Headword: 
achitonca.
Principal English Translation: 

a short time; soon

IPAspelling: 
ɑtʃihtoːnkɑ
Alonso de Molina: 

achitonca. vn poco de tiempo. aduerbio.
Alonso de Molina, Vocabulario en lengua castellana y mexicana y mexicana y castellana, 1571, part 2, Nahuatl to Spanish, f. 2r. col. 2. Thanks to Joe Campbell for providing the transcription.

Frances Karttunen: 

ACHIHTŌNCA soon, a short time / un poco de tiempo (M) See ACHI.
Frances Karttunen, An Analytical Dictionary of Nahuatl (Norman: University of Oklahoma Press, 1992), 2.

Horacio Carochi / English: 

achìtōnca= a short time
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), 354–55, 496.

Attestations from sources in English: 

achiton cahuitl = a little bit of time

çan huel achitonca = just a very short time (early seventeenth century, central New Spain)
Annals of His Time: Don Domingo de San Antón Muñón Chimalpahin Quauhtlehuanitzin, James Lockhart, Susan Schroeder, and Doris Namala, eds. and transl. (Stanford: Stanford University Press, 2006), 176–177.