belittle
To make someone or their ideas seem unimportant or small.
To belittle someone means to make them feel small, unimportant, or less capable than they really are. When you belittle another person, you dismiss their ideas, mock their efforts, or treat their accomplishments as if they don't matter.
Imagine a student who worked hard on a science project, only to have a classmate say, “That's easy, anyone could do that.” That's belittling. The comment makes the student's real effort seem worthless. Or picture someone sharing an idea in class and another student rolling their eyes and saying, “That's a dumb idea.” That response belittles both the idea and the person who shared it.
The word comes from “little,” and that's exactly what it does: it tries to make something or someone seem little or insignificant. You might hear someone say, “I don't mean to belittle your concerns, but...” which usually means they're about to do exactly that. When you disagree with someone, you can respect their perspective even while offering a different view. Belittling, by contrast, dismisses the person along with their ideas.