Is Synergy a strategy ?

Synergy is the creation of a whole that is greater than the simple sum of its parts. The term synergy comes from the Attic Greek word συνεργία synergia

Synergy is the philosophy that a strategy can be planned in.

There are different business structures, and synergy is the essence of many of the open and cooperative business structures. There can be different strategies that use synergy, but synergy does not have the defined end goal without strategy.  

Strategy is how to achieve a goal, synergy is a foundation for your entity.