to wound someone's head by throwing a rock at them; or to throw a rock at them (see Molina)
Orthographic Variants:
quatepachoa
Alonso de Molina:
quatepachoa. nite. (pret. onitequatepacho.) descalabrar a otro con piedra o dar pedrada. Alonso de Molina, Vocabulario en lengua castellana y mexicana y mexicana y castellana, 1571, part 2, Nahuatl to Spanish, f. 85v. col. 2. Thanks to Joe Campbell for providing the transcription.