zo'a FAhA4 -zon-zo'a- cmavo

location tense relation/direction; tangential to/passing by ...

In notes:

zonkai
x1 is alongside of x2
zo'anjo
x1 (linear manifold, vector, etc.) is/lies tangent to x2 (object, surface, curve, manifold, etc.) at point/locus x3, by standard/definition/in system x4.