Definitions

1. noun

A middle line or plane, especially one dividing the body into left and right parts; the line or plane that divides the body into symmetrical halves

“The midline of the face is the center line between the two eyes.”

2. noun

A middle line or position, especially one dividing a group or organization into opposing factions

“The midline between the two rival factions was the neutral zone.”

3. verb

to place or position something in the middle, especially a line or plane

“The artist midlined the canvas with a bold stroke of paint.”