Narrow-mindedness is the quality of being unwilling to accept or understand new or different ideas, opinions, or customs. A narrow-minded person keeps a tight little circle of “the right way” and treats anything outside it as wrong, strange, or not worth hearing. You meet the word when people talk about prejudice, closed groups, or someone who will not even try another side. It is not the same as having a firm belief: you can hold a belief and still listen. Narrow-mindedness is the shutting of the door. The word is a little formal and a little judging — we usually say it about other people, not about ourselves. Though actually, people also use it loosely, just to mean “they disagree with me,” which is not quite fair.