clearance

• 名词，指两个物体之间可供通过而不接触的空间，也指官方给予的许可或批准。

A noun referring to the space between two objects that allows one to pass without touching, or official permission or authorization to proceed with an action.

1. Space between objectsB2formal

   The distance by which one object passes another without touching; the gap or space between them.

   间隙

   • The bridge has a clearance of 15 feet for boats.
   • There is not enough clearance for the truck to pass under the low arch.
   • The mechanic checked the clearance between the piston and the cylinder wall.

   同义词allowancedistancegapintervalleewaymarginplayseparationspace

   反义词blockageclosureobstruction

2. Vertical space for passageB2formal

   The amount of vertical space available to allow easy movement or passage underneath something.

   净空高度

   • The sign indicated a low clearance of 12 feet ahead.
   • The van was too tall to fit under the bridge with only 10 feet of clearance.
   • The garage door provides a clearance of 7 feet for vehicles.

   同义词headway

3. Official permissionB1formal

   Authorization or permission to proceed with a particular action, especially in security or aviation contexts.

   许可

   • The pilot received clearance for takeoff from the control tower.
   • He was granted security clearance to access the classified documents.
   • We need clearance from the manager before we can start the project.

   同义词approvalauthorizationconsentgo-aheadgreen lightleavepermissionpermitsanction

   反义词bandenialprohibitionrefusal