to dumb down something 简化（非正式）

英文释义

(INFORMAL) To simplify something so that it will be extremely easy to understand by uneducated people. (NOTE: usually derogatory)

例句

I think the film director unfortunately felt the need to dumb down the beautiful old novel's complicated love story so he could make a popular movie out of it.

我认为，这部电影的导演不幸地感到，有必要将这部优美旧小说的复杂爱情故事简化一下，以便能拍成一部流行电影。