* eye-koh-sih-doh-deh-kah-hee-drun
Here's a breakdown:
* Ico - pronounced like "eye-koh"
* si - pronounced like "sih"
* do - pronounced like "doh"
* deca - pronounced like "deh-kah"
* hedron - pronounced like "hee-drun"
Let me know if you'd like to hear how to pronounce any other difficult words!