To intersect means to cross or meet at a point. When two roads intersect, they cross each other, creating an intersection where drivers must watch for traffic coming from different directions. When two lines intersect on a graph in math class, they touch at exactly one point.

Picture drawing an X: the two lines intersect right in the middle where they cross. Streets can intersect, paths in a park can intersect, and even ideas can intersect when they share common ground or overlap in interesting ways.

In geometry, you'll learn that parallel lines never intersect because they stay the same distance apart, like railroad tracks stretching into the distance. But lines that are not parallel will eventually meet somewhere if you extend them far enough.

The noun form is intersection, which is both the place where things cross and the act of crossing. When your teacher talks about the intersection of two subjects, like where history and science meet when studying the invention of the printing press, she means the place where both topics come together and connect.