tlaco (Mdz46r)
This element, which stands for the word "half" (tlaco), has been carved from the compound sign for the place name, Tlacotlalpan. It is a vertical, white or natural-colored half-circle, outlined in black ink. The left half of the circle could also be filed under "tlaco," along with "tlalli."
Stephanie Wood
The abstract concept of "half" of something is fairly easy to convey with half a circle. Also, given that people were extremely familiar with the round tortilla—the essential staple of Aztec/Nahua food—the second half of the tortilla would be a glaring omission. If people would think "tortilla" when seeing a circle, they might think of it as torn or folded in half. And a tortilla folded in half becomes a taco if it is filled with something. While we do not have any attestations in our dictionary where "tlaco" refers to a folded tortilla, "taco" and "tlaco" are near homophones. Today, the town name for the compound glyph (from which this element was carved) has changed from Tlacotlalpan to Tacotalpa (see Mexicolore), which provides some evidence of the equation of taco with tlaco.
Stephanie Wood
c. 1541, but by 1553 at the latest
halves, medio
tlaco, half, https://nahuatl.wired-humanities.org/content/tlaco
half
la mitad, o medio
Codex Mendoza, folio 46 recto, https://digital.bodleian.ox.ac.uk/objects/2fea788e-2aa2-4f08-b6d9-648c00..., image 102 of 188.
The Bodleian Libraries, University of Oxford, hold the original manuscript, the MS. Arch. Selden. A. 1. This image is published here under the UK Creative Commons, “Attribution-NonCommercial-ShareAlike 3.0 License” (CC-BY-NC-SA 3.0).