I'm writing a description that involves two curves behaving (approximately) as shown below. There aren't actually two intersections: they are mutually tangential. Also, I have many such curves, this is just a characteristic example. Something like $x^2$ and $2x^2$ at the origin is another example.
There are two important properties here. The first is that the curves are tangential. i.e. they touch with equal derivatives. The second important feature is that they "move away from each other" on either side of the point where they "touch". So, e.g. if you took the diffence between the two curves (say up is the $y$-axis) then you'd find it is growing.
I had been using the clunky "Curve A is tangential to and curved away from Curve B". Some suggested "Curve A osculates Curve B", but having looked up more about the word osculate, I'm not sure this is right. Although the examples I've seen of osculation would all satisfy my condition, the curve in the picture is not osculation, as I understand...
I did try to dig around for an answer here before asking, but without luck. Apologies if this question is a duplicate. Also, owing to its technical nature, I presume it's better off here than an English Usage SE.