snap line (noun)

1. The architect used a snap line to mark a straight line on the wall for the placement of the tiles.

2. In the horror movie, the ghostly figure used a snap line to create eerie chalk drawings on the walls.

3. The artist used a snap line to create a precise division between the colors on the canvas.

4. According to mythology, the god of architecture used a magical snap line to effortlessly create perfectly straight lines on vertical surfaces.