to keep oneself apart, to isolate oneself (reflexive) (see Molina)
Orthographic Variants:
atzaqua
Alonso de Molina:
atzaqua. nin. (pret. oninatzacu.) aislarse. Alonso de Molina, Vocabulario en lengua castellana y mexicana y mexicana y castellana, 1571, part 2, Nahuatl to Spanish, f. 9r. col. 1. Thanks to Joe Campbell for providing the transcription.