... When you add a measure to something to keep flow?
There has to be a name.
For example, lets say you have a 9-measure chorus, followed by a 8-measure body, back to the 9-measure chorus, then a 8-measure body, etc.
Is there a name for that extra measure there?
Here is the song that made me think of it:

https://sites.evergreen.edu/wp-content/uploads/sites/194/2016/06/A-Place-in-the-Choir.pdf
https://www.youtube.com/watch?v=-iP27eatYxE