Plain English Meaning

One fix on the approach chart that does two jobs. If you are coming from far out and need to fly the full approach, you treat it as the starting point. If you are already lined up close to final, you treat it as the point where the middle part of the approach begins.

Full Definition

A single charted fix on an instrument approach procedure that serves two functions at once: it is both an Initial Approach Fix (IAF), where the initial approach segment may begin, and an Intermediate Fix (IF), where the intermediate approach segment begins. Pilots arriving via a feeder route or transition use it as the IAF; pilots being vectored or arriving on a course aligned within the published use it as the IF, bypassing the initial entirely.