Apple Podcasts calls it "Consumption Rate." Spotify calls it "Episode Performance."
On other platforms, you may see it in the form of "Completion Rate" (Stitcher) or "Audience Retention" (Google Podcasts).
Regardless of what it's called, these represent the amount of listeners who haven't quit or left at some certain point during the episode. A higher number may indicate loyal fanbase or good quality episodes. It is also a good indicator of how effective your podcast is.