Isthmian
Mesoamerican writing system in use in the area of the Isthmus of Tehuantepec from perhaps 500 BCE to 500 CE
en-GB/ˈɪsθmɪən/
en-US/ˈɪsmiən/
Mesoamerican writing system in use in the area of the Isthmus of Tehuantepec from perhaps 500 BCE to 500 CE