to cover the ground with (adobe?) bricks (see Molina)
IPAspelling:
ʃɑmiʃkɑlmɑnɑ
Alonso de Molina:
xamixcalmana. nitla. (pret. onitlaxamixcalman.) enladrillar suelo. Alonso de Molina, Vocabulario en lengua castellana y mexicana y mexicana y castellana, 1571, part 2, Nahuatl to Spanish, f. 158v. col. 1. Thanks to Joe Campbell for providing the transcription.