cui.

Headword: 
cui.
Principal English Translation: 

to take, get, fetch, grasp; to take something; to take someone (see Lockhart and Karttunen)

IPAspelling: 
kwi
Alonso de Molina: 

Cui. nic. tomar algo, o tener parte el hombre cõ la muger. pret. oniccuic.
Cui. nocon. tomar or alcançar con la mano lo que esta en alto. pre. onoconcuic.
Alonso de Molina, Vocabulario en lengua castellana y mexicana y mexicana y castellana, 1571, part 2, f. 26v.

Frances Karttunen: 

CUI vt; pret: CUIC to take something or someone / tomar algo, o tener parte el hombre con la mujer (M) For all sources, with the exception of T, this verb consistently has a long stem vowel before the applicative and causative suffixes, but the vowel is never marked long before preterit -C . CUĪLŌ altern. nonact. CUI CUĪLTIĀ altern. caus.CUI
Frances Karttunen, An Analytical Dictionary of Nahuatl (Norman: University of Oklahoma Press, 1992), 71.

Horacio Carochi / English: 

cui = to take
Horacio Carochi, S.J., Grammar of the Mexican language with an explanation of its adverbs (1645), translated and edited with commentary by James Lockhart, UCLA Latin American Studies Volume 89 (Stanford: Stanford University Press, UCLA Latin American Center Publications, 2001), 128 n1, 129 n6, 500.

Lockhart’s Nahuatl as Written: 

nic. to take, get, fetch, grasp. Class 1: ōniccuic, cui, ana, to understand, profit from what one is told. (It is possible that the i of cui was once long.)
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), 216.

Attestations from sources in English: 

ayac quicuiliz = no one is to take it from him/her (formulaic phrase) Beyond the Codices, eds. Arthur J.O. Anderson, Frances Berdan, and James Lockhart (Los Angeles: UCLA Latin American Center, 1976), 28.

At concujzque, at conanazque, at conmopialtizque = Perhaps they will grasp it, take it, hold fast to it (central Mexico, sixteenth century)
Fr. Bernardino de Sahagún, Florentine Codex: General History of the Things of New Spain; Book 6 -- Rhetoric and Moral Philosophy, No. 14, Part 7, eds. and transl. Arthur J. O. Anderson and Charles E. Dibble (Santa Fe and Salt Lake City: School of American Research and the University of Utah, 1961), 83.

Attestations from sources in Spanish: 

ayac quicuiliz on onechmacaque yca justicia = y nadien se la quite, la que me dieron por la justicia
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), 224-225.

verbo transitivo, te-, casarse con alguien. Literalmente, tomar a alguien, que es su sentido original.
Thelma Sullivan, Documentos Tlaxcaltecas del siglo XVI en lengua náhuatl (Mexico: Universidad Nacional Autónoma de México, 1987), 40.