Hi,
I hope this hasn’t been discussed somewhere else.
Is there a reason why we call it a stopover and not a waypoint or via-point? Stopover implicates that one should actually stop. It’s not really a pressing issue, but for example for Kurviger is sometimes receive the question why it’s called a stopover and I got to admit that this indeed is question, worth asking :).
Best,
Robin
Interesting question. 
Indeed stopover is not common among most routing engines.
My vote would go for the usual “Waypoint” term.
waypoint is also used in the response and so I would be fine with it. I also added a note to (possibly) rename point to waypoint in next API version: https://github.com/graphhopper/graphhopper/issues/437
Thanks for the discussion, I created a PR for this.