Principal English Translation: 

a straightened reed (usually also hardened over a fire, for use in making arrows) (see Sahagún, translated by Thelma Sullivan, below)

Attestations from sources in English: 

Itzuitequi, acamelaoa. Inin tlatolli, itechpa mitoaya: in aquin tecocolitinemi, teuey yecoitinemi = An arrow that wounds, a reed that is straightened. These words were siad about one person who hated another was constantly plotting to do something monstrous to him. Thelma D. Sullivan, "Nahuatl Proverbs, Conundrums, and Metaphors, Collected by Sahagún," Estudios de Cultura Náhuatl 4 (1963), 155–156.