Principal English Translation:
close familial relationship, such as brother-in-law; sister-in-law; etc.
Alonso de Molina:
uepollotl. parentesco de afinidad y cuñadez
Alonso de Molina, Vocabulario en lengua castellana y mexicana y mexicana y castellana, 1571, part 2, Nahuatl to Spanish, f. 156v. col. 2. Thanks to Joe Campbell for providing the transcription.
Attestations from sources in English:
cuix nelli quichiuaznequi preytos ynic nechixnamiquiz quil quitlaniznequi arimentos yn amohuepol coyouaca = is it true? -- that your brother-in-law who is in Coyoacan wants to bring suit complaining against me (Mexico City, 1598)
Beyond the Codices, eds. Arthur J.O. Anderson, Frances Berdan, and James Lockhart (Los Angeles: UCLA Latin American Center, 1976), Doc. 33, 206–207.
-huepol = the form, when possessed, for one's same-generation in-law of the opposite gender
Caterina Pizzigoni, ed., Testaments of Toluca (Stanford: Stanford University Press and UCLA Latin American Center Publications, 2007), 40.
Attestations from sources in Spanish:
yn tehuantzin yn tinouepoltzin = tu que eres mi cuñado
Vidas y bienes olvidados: Testamentos indígenas novohispanos, vol. 1, Testamentos en castellano del siglo XVI y en náhuatl y castellano de Ocotelulco de los siglos XVI y XVII, eds. Teresa Rojas Rabiela, Elsa Leticia Rea López, y Constantino Medina Lima (Mexico: CIESAS, 1999), 214–215.