General synonyms:
* Created
* Constructed
* Produced
* Manufactured
* Composed
* Formulated
* Fabricated
* Assembled
More specific synonyms, depending on the context:
* Artificial (if referring to something made artificially)
* Combined (if referring to combining elements)
* Derived (if referring to something created from other sources)
* Generated (if referring to something created by a process)
* Integrated (if referring to combining different parts)
For music:
* Arranged
* Composed
* Orchestrated
* Improvised
For science/chemistry:
* Prepared
* Extracted
* Condensed
* Isolated
For language/writing:
* Summarized
* Paraphrased
* Condensed
* Abstracted
To choose the best synonym, consider the specific meaning of "synthesized" in your context and select a word that best conveys that meaning.
