Clearance (noun)

1. The process of removing or getting rid of something, especially by authority or permission.
2. The distance between a surface and an obstacle or other surface, especially the minimum distance required for safety or comfort.
3. The authorization or permission given to a person, product, or vehicle to proceed, especially through customs or security checks.
4. The amount by which a discount is given on the original price of an item during a sale.

Origin:

Derived from the old french word 'clairer', meaning 'to make clear'.

Examples:

1. The workers had to wait for clearance to enter the construction site.
2. The aircraft had a minimum clearance of 200 feet above the terrain.
3. He had to show his passport and get clearance from customs before he could enter the country.
4. The store was offering a 50% clearance on all winter clothing.
5. She needed clearance from her supervisor before she could start the project.