What is the Greek word for federation?

There isn't one single perfect Greek word for "federation" that captures all its nuances. The best choice depends on the specific context. However, some possibilities include:

* Ομοσπονδία (Omospondia): This is probably the closest single word and is frequently used. It implies a union or alliance of states.

* Combinations of words might be more precise depending on the type of federation: for example, a combination of words relating to "state" (κράτος - krátos) and "union" (ένωση - énosis) could be used to create a more descriptive phrase.

Therefore, while Ομοσπονδία (Omospondia) is the most common and readily understood translation, a more precise rendering might require a phrase rather than a single word.