Complex sentence: In reference to aircraft, chord refers to the distance between the front and back of a wing, measured in the direction of the normal airflow, also known as the "leading edge" and "trailing edge".
Split into simpler sentences: In reference to aircraft, chord refers to the distance between the front and back of a wing, measured in the direction of the normal airflow. In typically usage these points are referred to as the "leading edge" and "trailing edge".