ihuan.

Headword: 
ihuan.
Principal English Translation: 

and, along with, with

Orthographic Variants: 
yhuan, iuan, ivan, yoan
IPAspelling: 
iːwɑːn
Alonso de Molina: 

iuan. y. y tambien. conjunction.
Alonso de Molina, Vocabulario en lengua castellana y mexicana y mexicana y castellana, 1571, part 2, Nahuatl to Spanish, f. 43v. col. 1. Thanks to Joe Campbell for providing the transcription.

Frances Karttunen: 

ĪHUĀN in the company of something or someone else, and / y, y también (M) The third person singular possessed form of the postposition –HUĀN has virtually the function of a conjunction. In T and Z it has lost the possessive prefix Ī- and been lexicalized as HUĀN ‘and.’ In T the final N is also lost by general rule. See –HUĀN.
Frances Karttunen, An Analytical Dictionary of Nahuatl (Norman: University of Oklahoma Press, 1992), 101.

Attestations from sources in English: 

yoan teuanti talldsme = and we alcaldes (Coyoacan, 1557)
Beyond the Codices, eds. Arthur J.O. Anderson, Frances Berdan, and James Lockhart (Los Angeles: UCLA Latin American Center, 1976), Doc. 12, 92–93.

i-huan = 3rd person singular possessed form of -huan
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), 220.

ynhua, ynhuahua = and
Miriam Melton Villanueva and Caterina Pizzigoni, "Testament of Margarita Feliciana, San Bartolomé Tlatelolco, 1823," pp. 4–5, Early Nahuatl Virtual Library Project, Wired Humanities, University of Oregon, http://whp.wired-humanities.org/nahlib/envlp/Tlatelolco1.pdf

yhuan huel iuh = and likewise
Robert Haskett and Stephanie Wood's notes from Nahuatl sessions with James Lockhart and subsequent research.

Attestations from sources in Spanish: 

uan = ihuan
Naja a:huil tit ne a:mat se tzunzu:cul uan at. = Yo dibujo en el cuaderno un ca:ntaro con agua. (Sonsonate, El Salvador, Nahuat or Pipil, s. XX)
Tirso Canales, Nahuat (San Salvador: Universidad de El Salvador, Editorial Universitaria, 1996), 7–8.