Principal English Translation:
for god’s sake (an expression of surprise at a discovery) (see Karttunen)
Horacio Carochi / English:
tlacàço = interjection, I'll be
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), 513.