"Started on" refers to the beginning of an action or process that has been initiated or commenced. There are various synonyms that can be used interchangeably to describe this concept. Some examples include "began", "commenced", "initialized", "inaugurated", "initiated", "launched", "triggered", and "embarked upon". Each of these words may convey slightly different nuances depending on the context in which they are used, but they all share the common meaning of starting something. By using synonyms for "started on", writers can avoid repetition and add variety to their prose while still conveying the intended message.