Inducers refer to substances that prompt the occurrence of a particular event or reaction. Synonyms for inducers include catalysts, initiators, motivators, instigators, stimulators, and provokers. Catalysts are substances that accelerate the occurrence of a chemical reaction without being consumed themselves. Initiators refer to substances that start a particular reaction. Motivators are individuals or things that encourage or provoke someone to do something. Instigators, on the other hand, refer to people who encourage or provoke others to engage in a particular activity. Stimulators describe substances that encourage or enhance the activity of a particular organ or tissue. Finally, provokers are people or things that cause someone to feel anger or irritation.