There are several synonyms for the term "idea man" that communicate the same meaning. One common alternative is "creative genius," which suggests someone with a natural talent for generating innovative concepts and solutions. Another option is "visionary," which implies an individual with a unique and forward-thinking perspective on the world. "Innovator" is another synonym that conveys a similar idea, highlighting someone who is able to develop and implement groundbreaking ideas. Finally, the term "brainstormer" can be used to describe someone who excels at generating a large number of creative ideas in a short amount of time.