Lyle Campbell, American Indian Languages: The Historical Linguistics of Native America (ISBN 0195349830, 2000): Maratino chiguat [čiwat] 'woman' is a borrowing from Aztec siwa:tl, as is peyot 'peyote' (from Nahuatl peyotl).
Etymology
Clearly related in some way to Nahuatlcihuatl; Campbell considers the Marantino term a borrowing of the Nahuatl term; Swanton had considered Marantino Uto-Aztecan based on the idea that they were cognate.