to flatten the ground by filling up the holes (see Molina)
Alonso de Molina:
ixtema. nitla. (pret. onitlaixten.) allanar hinchendo de tierra los hoyos. &c. Alonso de Molina, Vocabulario en lengua castellana y mexicana y mexicana y castellana, 1571, part 2, Nahuatl to Spanish, f. 47v. col. 1. Thanks to Joe Campbell for providing the transcription.
Frances Karttunen:
ĪXTĒM(a) vt: pret: ĪXTN to fill something up, to level something, to top something off / lo rellena, lo empareja (T), allanar hinchendo de tierra los hoyos (M) [(6)Tp.218,230]. See ĪX-TLI, TĒM(A).