firmaroa.

(a loanword from Spanish)

Headword: 
firmaroa.
Principal English Translation: 

to sign, add a signature
(from firmar, a Spanish loanword)

Frances Karttunen and James Lockhart, Nahuatl in the Middle Years: Language Contact Phenomena in Texts of the Colonial Period, Linguistics 85 (Los Angeles, University of California Publications, 1976), 32.

Orthographic Variants: 
firmarohua
Lockhart’s Nahuatl as Written: 

Class 3: ōnicfirmāroh. Sp. firmar, -oa. Sp.
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), 217.

Attestations from sources in English: 

nicfirmarohua ... ticfirmarohua mochi y testigos (Centlalpan, Chalco, 1736) The authors add: also seen as firmarohua; this is a loan from Spanish, firmar, with the -oa ending added, as was the custom by 1700 for Nahuatlizing a Spanish verb; this new verb loan would then be conjugated and have added reverential, applicative, direct and indirect object markers: e.g. onicfirmaro = I signed it.
Frances Karttunen and James Lockhart, Nahuatl in the Middle Years: Language Contact Phenomena in Texts of the Colonial Period, Linguistics 85 (Los Angeles, University of California Publications, 1976), Doc. 10.

Oquimofirmarhui in toapoderadotzin = our proxy signed for us (Azcapotzalco, 1738)
Beyond the Codices, eds. Arthur J.O. Anderson, Frances Berdan, and James Lockhart (Los Angeles: UCLA Latin American Center, 1976), Doc. 17, 102–103.

themes: 
Writing, Literacy