a seat or mound upon which people were sacrificed to be offerings to the deities or divinities (see attestations)
The use of this term in the Historia Tolteca-Chichimeca is somewhat ambiguous. It appears that the four young women who were offered to the Nonoalca Chichimeca did not have large enough buttocks, and so the Nonoalca became angry and tied the women to an itztehuepalli (so that they would be sacrificed). The discussion about the measurements of their buttocks is interesting; larger buttocks were preferred over smaller ones. The young women were also apparently virgins, and this was apparently part of what was not desired, along with the small size of their bottoms. (sixteenth century, Quauhtinchan)
"[S]ignifica literalmente 'obsidiana-tabla'.... itztapal e itzteuepal son sinónimos...losa de obsidiana," un lugar para sacrificar a Itztapaltotec o a Xipetotec. (Quauhtinchan, s. XVI)