Hi, not sure if this is the correct place to post, probably not! So sorry
Can anyone tell me if there is a name for this effect look that is (and has been) used when working with 4:3 footage to fill a 16:9 frame.

You are basically copying the last few pixels from the 4:3 frame and pasting them to cover up the black vertical space (in other words, filling up the frame). Obviously a blur has been added to the repeated pixels as not to draw attention away from the original 4:3 image.
I hope this makes sense and i hope my embedded image comes out!