Final answer:
The clearance limit is a fix on an instrument approach procedure from which the final approach segment begins in aviation.
Step-by-step explanation:
In aviation, the clearance limit refers to a fix on an instrument approach procedure from which the final approach segment of the procedure begins. This fix is typically located along the approach course, and it is where pilots are cleared to descend further towards the runway and continue with the approach. The clearance limit ensures safe separation between aircraft and provides a defined starting point for an approach.