break the neck, and, by extension, to cut off someone's head or decapitate someone; and see attestations for additional translations
çan quechcotonalloque cenpohuallonchiuhiuhcnahui yn omoteneuhque mimicque auh yn intzonteco oncan tepilolcuauhticpac quinçaçalloque, auh yn intlacnacayo oncan quincallaquique yn contadoria tlatzĩtla = 29 of the said dead were only decapitated and their heads stuck on top of the gallows. They put their torsos in the royal accounting office, down below, (central Mexico, 1612)
yn oquechcotonalloque. omentin tlahtoque Alonso davilla. yhuan yteyccauh Gil goçales aluarado. yaoyotl yntech tlah quichihuazquia. yuh mito macocuizquia. yn ipampa quitzauhtiaque. = the two lords Alonso de Avila and his younger sibling Gil González de Alvarado were decapitated. They were accused of being about to make war. It was said that they were going to rebel, for which they paid the penalty. (1608, Central Mexico)
Also seen defined in relation to the ritual sacrifice of an animal.
To cut or harvest fruits, flowers, etc.
And: to pick an ear of grain with one's hand.
nican moyolcuep quiquechcotoque y cepan don Alonso de Avila don Pedro. = que aquí se había rebelado. Decapitaron juntos a don Alonso Dávila y a don Pedro [Quezada]. (Tlaxcala, 1662–1692)
Oy sabado [Sobre el renglón: sabado] a tres dias del mes de ag[ost]o de 1566 yquac quechcotonaloque yn Alonso Davilla yhuan yteiccauh Gilli Gonçalis Davilla = Hoy sábado a tres días del mes de agosto de 1566, entonces fueron decapitados Alonso Dávila y su hermano menor Gil González Dávila (ca. 1582, México)