acaxitl. alberca. Alonso de Molina, Vocabulario en lengua castellana y mexicana y mexicana y castellana, 1571, part 2, Nahuatl to Spanish, f. 1v. col. 2. Thanks to Joe Campbell for providing the transcription.
Frances Karttunen:
ĀCAX(I)-TL pl: -TIN watering trough /K001/ alberca (M), pileta para tomar agua los animales (X)[(3)Xp.25]. X fails to mark the initial vowel long. See Ā-TL, CAX(I)-TL. Frances Karttunen, An Analytical Dictionary of Nahuatl (Norman: University of Oklahoma Press, 1992), 1.