-mach.

Headword: 
-mach.
Principal English Translation: 

secondary particle; intensifies dubitative particles and interrogatives, often can be translated as the devil, in the world, in heaven's name, etc.

James Lockhart, Nahuatl as Written: Lessons in Older Written Nahuatl, with Copious Examples and Texts (Stanford: Stanford University Press and UCLA Latin American Studies, 2001), 223.

Attestations from sources in English: 

mach (adverb) = an intensive particle
Daniel Garrison Brinton, Ancient Nahuatl Poetry: Containing the Nahuatl Text of XXVII Ancient Mexican Poems (1877), 157.

themes: 
Religion (Christian)