1. in a direction or manner that is at right angles (90 degrees) to a surface or line
2. in a steep or nearly vertical manner

Examples

• The ladder was leaning perpendicularly against the wall.
• The rain fell perpendicularly from the sky.
• The cliff dropped perpendicularly into the ocean.
• The two lines intersect perpendicularly at the center of the diagram.
• She held the pencil perpendicularly to the paper to make a straight mark.
• The bridge's support beams run perpendicularly to the main structure.