-ixcoyan.

Headword: 
-ixcoyan.
Principal English Translation: 

one's very own (must be possessed)
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), 221.

IPAspelling: 
-iːʃkohyɑːn
Frances Karttunen: 

-ĪXCOHYĀN necessarily possessed form something of one’s own, something personally owned, proper to oneself or its purpose / propio, personal, particular (S), solo (Z) This is abundantly attested in C where it is given as synonymous with NOHMAH. Bf. 11V has ĪXCOCA, which from context appears to mean ‘one’s bussiness, one’s own responsibility.’ It would seem to be derived in some indirect way from –ĪXCO. See ĪX-TLI,-C(O),-YĀN.
Frances Karttunen, An Analytical Dictionary of Nahuatl (Norman: University of Oklahoma Press, 1992), 112.

Lockhart’s Nahuatl as Written: 

behaves rather like a relational word, looks rather like a deverbal locative noun. constituent elements not clear. 221

Attestations from sources in English: 

nīxcohyān notlatqui = my very own property
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), 221.

Attestations from sources in Spanish: 

nixcoyan omocuentique yn tococolvan yn totavan = personalmente se adueñaron de ellas [las tierras?] nuestros abuelos y papas (Tlaxcala, 1568)
Catálogo de documentos escritos en náhuatl, siglo XVI, vol. I (Tlaxcala: Gobierno del Estado de Tlaxcala y el Archivo Histórico del Estado de Tlaxcala, 2013), 123.ypanpa yn amo totecuio dios nechmotlatzacuiltiliz nicnomaquilia yn omoteneuh nixcoyan notepancal = porque Dios nuestro señor no me castigará si le diera mi dicho corral (Tetzcoco, 1610)
Benjamin Daniel Johnson, “Transcripción de los documentos Nahuas de Tezcoco en los Papeles de la Embajada Americana resguardados en el Archivo Histórico de la Biblioteca Nacional de Antropología e Historia de México”, en Documentos nahuas de Tezcoco, Vol. 1, ed. Javier Eduardo Ramírez López (Texcoco: Diócesis de Texcoco, 2018), 158–159.