"federates" in the verb sense
1. federate, federalize, federalise
enter into a league for a common purpose
"The republics federated to become the Soviet Union"
2. federate, federalize, federalise
unite on a federal basis or band together as a league
"The country was federated after the civil war"
Source: WordNet® (An amazing lexical database of English)
Princeton University "About WordNet®."
WordNet®. Princeton University. 2010.
View WordNet® License