tlaelatl.

in tequisquiatl, in tlaelatl = the nitrous water, the dirty water (a metaphor for original sin) (16th-c. central Mexico)
John F. Schwaller, "The Pre-Hispanic Poetics of Sahagún's Psalmodia christiana," in Psalms in the Early Modern World, eds. Linda Phyllis Austern, Kari Boyd McBride, and David L. Orvis (London: Ashgate, 2011), 321. Cites Bierhorst, Cantares Mexicanos, 252–253.