Narrowness is the quality of being narrow, or not wide. A hallway might have such narrowness that two people can barely walk side by side. A mountain trail's narrowness might mean hikers need to go single file, especially around steep cliffs.

The word also describes limited thinking or perspective. When someone shows narrowness of mind, they refuse to consider new ideas or different viewpoints. A student who insists there's only one right way to solve a problem, even when classmates suggest creative alternatives, demonstrates this kind of narrowness. Sometimes called narrow-mindedness, this attitude can close people off from learning and growth.

Narrowness can describe anything that feels confined or restricted. The narrowness of a topic means it covers only a small slice of a bigger subject. Someone might criticize a book for the narrowness of its research if the author only looked at one side of an issue. The narrowness of your experience with something reflects how little exposure you've had to it.

Physical narrowness is neutral: sometimes you need a narrow opening or a slim space. But narrowness of thinking or perspective usually limits possibilities.