What is the Greek word of vegetarian?

There isn't a single, universally accepted Greek word for "vegetarian." Ancient Greeks didn't have the same dietary distinctions we do today. However, you could use descriptive phrases depending on the context:

* λαχανόφαγος (lachanopagos): This literally translates to "vegetable eater" and would be the closest single word approximation. However, it's not a commonly used term.

* You could also use a descriptive phrase like αυτός/αυτή που δεν τρώει κρέας (aftos/afti pou den troei kreas): This means "he/she who doesn't eat meat," which accurately describes a vegetarian.

So, while there's no perfect equivalent, λαχανόφαγος is the closest single word, but a descriptive phrase is often clearer and more readily understood.