What is the synonym for word initiated?

Here are some synonyms for "initiated," depending on the context:

General:

* Started

* Began

* Launched

* Commenced

* Opened

* Established

* Founded

* Introduced

* Set in motion

Formal:

* Inaugurated

* Embarked

* Undertaken

Informal:

* Kicked off

* Got going

* Got underway

Specific to groups:

* Inducted

* Welcomed

* Admitted

Specific to actions:

* Triggered

* Sparked

* Stimulated

The best synonym will depend on the specific meaning and context of the word "initiated" in your sentence.