What is a line through a circle called?

The line that intersects a circle can be called a diameter, a secant or a chord. The proper term depends on the line's properties and where the line intersects the circle.

The diameter of a circle is a line segment that intersects two points on the circle's circumference and crosses through the circle's center. The diameter splits a circle into two equal halves. According to Math Open Circle, if a line segment intersects any two points on a circle, it is called a chord. A secant, like a chord, intersects a circle at two points; however, a secant is a line that extends beyond the boundaries of the circle's circumference to infinity. A chord, on the other hand, only exists within the circle's boundaries.