The phrase "groundbreaking idea" can be replaced with a variety of synonyms that convey the same sense of innovation and originality. A "game-changing concept" implies that the idea has the potential to revolutionize the industry or market. An "innovative breakthrough" suggests that the idea is a significant advancement from previous notions. A "pioneering proposal" highlights the idea's novelty and the fact that it is the first of its kind. A "trailblazing innovation" implies that the idea is breaking new ground and paving the way for others to follow. Whatever term is used, the underlying meaning remains the same: an idea that is fresh, exciting, and has the potential to create significant impact.