* γάμος (gamos): This is the most common and widely understood word. It refers to the marriage *ceremony* itself, or sometimes the marriage *institution*. It's the closest single-word equivalent.
* γάμος γάμου (gamos gamou): This literally translates to "wedding wedding," emphasizing the event. It's more colloquial and might be used informally to talk about a specific wedding celebration.
Therefore, γάμος (gamos) is the best single-word answer.