noun
headway
The vertical space available beneath an overhead obstruction.
The low bridge leaves too little headway for tall trucks.
Etymology
The compound names room available above a person’s head. It extended to vertical clearance beneath bridges, ceilings, and other obstructions.
More examples
- There is barely enough headway to stand beneath the beam.
- The architect checks the headway above the basement stairs.
- Rising water reduces the headway beneath the bridge.
Forms
headway
Similar words
- headroom
- The more usual term for available space overhead.
- clearance
- Covers space around an object, not just above it.