chord.

About chord

In aeronautics, the chord is an imaginary straight line segment joining the leading edge and trailing edge of an aerofoil cross section parallel to the direction of the airflow. The chord length is the distance between the trailing edge and the leading edge. The point on the leading edge used to define the main chord may be the surface point of minimum radius. For a turbine aerofoil, the chord may be defined by the line between points where the front and rear of a 2-dimensional blade section would touch a flat surface when laid convex-side up.