I can find the term 'peak frame rate' in some video editing software.
Are 'peak frame rate' and 'variable frame rate' the same thing?
There are 'constant frame rate' and 'variable frame rate' both having obvious meanings: https://www.bandicam.com/support/tips/vfr-cfr/
https://en.wikipedia.org/wiki/Variable_frame_rate
https://handbrake.fr/docs/en/latest/technical/frame-rates.html
When you use VFR then you can select which are the minim, averaged and maximum frame rates. And that maximum is the same as "peak" frame rate.