* ISS-muss of te-wahn-te-PEK
Here's a breakdown:
* ISS-muss: The "th" sound is similar to the "th" in "thin" or "think."
* te-wahn-te-PEK: The "te" is pronounced like "tay," the "wahn" like "wan," and the "PEK" with a strong emphasis on the "P."
You can also find audio pronunciations online by searching "Isthmus of Tehuantepec pronunciation."