When you oversimplify, you describe something in a way that is too simple and leaves out many facts. The picture you give is easy to hold, but it is not really true — or not true enough. People oversimplify when they are in a hurry, when they want a clean story, or when they do not know the messy parts. News, teachers, and people in power do it; so do friends at dinner. It is not always a lie. The speaker often believes the simple version. You can oversimplify a problem, a war, a science idea, or a person. "Don't oversimplify" is a common warning: keep the hard bits in. The word is a little formal, but you meet it in class and in newspapers. Though actually, in everyday talk people often just say "you're making it sound too simple" or "it's not that simple." Simplify can be kind — you make an idea easier to learn. Oversimplify is when you go too far and the easy version starts to cheat.

過度簡化