Principal English Translation:
all at once, one time, once
Frances Karttunen:
CEMI once and for all, ultimately; always / finalmente, una sola vez, de repente (S), siempre (T), muy (Z) In Z, which has the variant forms CEMI ~ CIMI this has come to be a general intensifier meaning very or ‘very much’.
Frances Karttunen, An Analytical Dictionary of Nahuatl (Norman: University of Oklahoma Press, 1992), 29.
Horacio Carochi / English:
cemi = all at once
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), 464-65, 499.
Attestations from sources in English:
one time, once
Robert Haskett and Stephanie Wood's notes from Nahuatl sessions with James Lockhart and subsequent research.
Attestations from sources in Spanish:
auh cemi ce teotl ce Dios = un solo Dios (Tepexi de la Seda, 1621)
Vidas y bienes olvidados: Testamentos en náhuatl y castellano del siglo XVII, vol. 3, Teresa Rojas Rabiela, et al, eds. (México: CIESAS, 2002), 104–105.