Tlacuilolatl (MH779v)

The Acuicuil name glyph from this same manuscript has a swirl at the top, which one might have expected to see here, too. But this water does not swirl.

Marc Thouvenot identifies the verb icuiloa (or ihcuiloa, with the glottal stop), which means to paint, write, or print, as having a root of -cuil-. He notes how it also appears in tlacuiloliztli (writing), tlacuilo (writer), and cuicuiltic (mottled). He goes on to show various uses of icuiloa that take it beyond the simple definitions just given, resulting in something like the action of creating a design (e.g., on leather, ceramics, sculpture, or in textiles). It can also be something like the action of decorating (e.g., to put a flower on a cup of atole). He associates icuiloa and tlacuilolli with "cultural artifacts," such as arts and crafts or examples of writing and painting, but cuicuiltic with effects created by "nature." This short summary barely does his article justice; it is worth reading the entire piece. How Thouvenot's study might connect with the concept of bent or curved mentioned by Prem (1974: 555, 682) raises an interesting question. Perhaps the bent or curved lines of writing, painting, carving, embroidery, and so on, fall with in the realm of expressions of -cuil-. See
Marc Thouvenot, "Imágenes y escritura entre los nahuas del inicio del XVI," Estudios de Cultural Náhuatl 41 (2010).