‘freeride’ is not a word, it’s the value of an OSM tag.

I understand piste:difficulty=novice/easy/ … /freeride/extreme is intended to be a progressive scale that was later applied with the same values for piste:type other than downhill.
Could have been piste:difficulty=1/2/3/…

Now piste:difficulty=freeride stands out from the list of values, it is something different in natural language.

A bit of archeology:
The value difficulty=freeride appeared on the wiki in 2007, associated with european ‘yelow pistes’.
https://wiki.openstreetmap.org/w/index.php?title=Piste_Maps&oldid=43021

The first definition of piste:type=skitour:
https://wiki.openstreetmap.org/w/index.php?title=Piste_Maps&oldid=363081#Type

And the piste:difficulty applied to skitour baxk in 2009:
https://wiki.openstreetmap.org/w/index.php?title=Piste_Maps&oldid=378735#Difficulty

So, my understanding is that applied to piste:type=skitour, piste:difficulty=freeride just means SAC “AS”, ausserordentlich schwierig = “Exceptionally Difficult” in OSM tags. Nothing to do with natural word ‘freeride’.