- The definition of headroom is the space between your head and something over your head such as a doorway or the top of a vehicle, or the space between a vehicle and bridges or other structures that may be over that vehicle.
The space you have been your head and the car's roof is an example of headroom.
- space or clearance overhead, as in a doorway, tunnel, etc.
- the temporary increase in volume or power that a high-fidelity audio component can accommodate without distortion
- Space above one's head, as in a motor vehicle, above a doorway, or in a tunnel; clearance.
- See dynamic headroom.
headroom - Computer Definition
Attenuation-to-crosstalk ratio (ACR). See ACR.