to cover something up with earth, or to bury something or someone under a mound (see Molina and Karttunen)
IPAspelling:
tɬɑːlpɑtʃoɑː
Alonso de Molina:
tlalpachoa. nitla. (pret. onitlatlalpacho.) cubrir algo con tierra, o aporcar. Alonso de Molina, Vocabulario en lengua castellana y mexicana y mexicana y castellana, 1571, part 2, Nahuatl to Spanish, f. 124v. col. 1. Thanks to Joe Campbell for providing the transcription.
Frances Karttunen:
TLĀLPACHOĀ vrefl, vt to be buried; to bury something, someone / se entierra, se sepulta (T), cubrir algo con tierra o aporcar (M), lo sepulta, lo entierra (T) [(6)Tp.161,211]. See TLĀL-LI, PACHOĀ.
TLĀLPACHILHUIĀ applic. TLĀLPACHOĀ.
TLĀLPACHŌLŌ nonact. TLĀLPACHOĀ. Frances Karttunen, An Analytical Dictionary of Nahuatl (Norman: University of Oklahoma Press, 1992), 276.