straight line - a line traced by a point traveling in a constant direction; a line of zero curvature; "the shortest distance between two points is a straight line"line - a length (straight or curved) without breadth or thickness; the trace of a moving point asymptote - a straight line that is the limiting value of a curve; can be considered as tangent at infinity; "the asymptote of the curve" tangent - a straight line or plane that touches a curve or curved surface at a point but does not intersect it at that point secant - a straight line that intersects a curve at two or more points radius - a straight line from the center to the perimeter of a circle (or from the center to the surface of a sphere) diameter - a straight line connecting the center of a circle with two points on its perimeter (or the center of a sphere with two points on its surface) chord - a straight line connecting two points on a curve element - a straight line that generates a cylinder or cone bias, diagonal - a line or cut across a fabric that is not at right angles to a side of the fabric diagonal - (geometry) a straight line connecting any two vertices of a polygon that are not adjacent vector - a straight line segment whose length is magnitude and whose orientation in space is direction |