Final answer:
The clearance limit is the point from which an IFR approach begins in the event of lost communications according to standard aviation procedures detailed in the AIM.
Step-by-step explanation:
In the context of lost communications for an instrument flight rules (IFR) flight, the clearance limit is indeed the fix from which an approach begins. If a pilot flying under IFR loses communication with air traffic control (ATC), they are expected to proceed to the clearance limit and then, if at the clearance limit before the expected further clearance (EFC) time, enter a hold until that time. At the EFC time, or upon arrival at the clearance limit if that occurs after the EFC time, they should commence the approach based on the last assigned, vectored, expected or filed approach as per their flight plan and ATC instructions as part of the lost communications procedures detailed in the Aeronautical Information Manual (AIM).