To belittle someone or something is to make them seem small or unimportant — not by shrinking them in the real world, but by the way you talk. You belittle a person's work when you wave it away as nothing much; you belittle a worry when you laugh as if it were silly. It is an unkind verb, and people feel it in the chest. It is not quite the same as a loud insult: the hurt often comes from the shrinking, from being treated as less. The word sounds a little careful, even formal, but it is ordinary in speech when someone wants to name that shrinking clearly. Parents, teachers, and workplaces all know the pattern. Though actually, Thomas Jefferson coined it in 1782 from be- ('to make') and little, and some British writers at the time wrinkled their noses at it as a new American word. It stayed, because the need for a verb that means 'make little' stayed. You belittle a person, an idea, a success, a fear — the object is whatever you are trying to cut down to size.