malacayo.

Headword: 
malacayo.
Principal English Translation: 

the conjunction of branches and leaves that makes the exterior of the tree (like the canopy) (see Molina)

Alonso de Molina: 

malacayo. arbol copado.
Alonso de Molina, Vocabulario en lengua castellana y mexicana y mexicana y castellana, 1571, part 2, Nahuatl to Spanish, f. 51v. col. 1. Thanks to Joe Campbell for providing the transcription.

Attestations from sources in English: 

in totechiuhcaoan, in vel vevetque, in vel ilamatque muchiuhtiuj: in vel ceoallotiuj, in vel malacaiotivi, in vevei puchotl, avevetl muchiuhtivi yn ointlannecalaqujloc: auh in amo ointlan cahaqujco in jmma, in jmjcxi: in oqujҫoҫoaco in jmahaz, in jncujtlapiltzin = These were our forefathers who lived as the really old men, the really old women, who went casting a shadow, who went providing shade, who went forming the great silk cotton trees, the cypresses for those who became their subjects. And they were the ones who went not hiding their hands, their feet; rather, those who went extending their wings, their tail feathers (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), 137.