noun. A line that bisects something into equal parts.

noun. A painted line running along the center of a road or highway that divides it into two sections for traffic moving in opposite directions, or, in the case of a divided highway, for lines of traffic moving in the same direction at different speeds.

noun. A line that divides a shape into equal pieces.

noun. a line that bisects a plane figure

"Negative offset means the centerline is outboard of the mounting surface; positive offset means the centerline is inboard of the mounting surface."

line  

angulation  center-line  coordinate  girder  scrollbar