I'm now officially confused about the usage of "tangential" when breaking down orbital velocity components. It started with edits and comments on this answer to Orbital speed is (vector) sum of tangential and normal speed?
I've (possibly/probably incorrectly) used "tangential" to refer to the velocity component perpendicular to radial in Low-thrust spiraling to escape, is the flight path angle (gamma) at C3=0 always 39 degrees? and also in How to calculate the flight path angle, γ, from a state vector?. I say possibly/probably inccorectly because the the velocity should always be tangent to the orbit. But rather than correct me, @MarkAdler's answer to the first question continues the distinction between tangential velocity and the direction of motion:
Below is the same plot for when accelerating tangentially, as opposed to in the velocity direction.
and @TomSpilker's answer to the second question does likewise:
In addition to $\gamma$, the angle between the tangential direction and the velocity vector, there is $\beta$, the angle between the radial direction and the velocity vector.
However, the diagram below from Julio@'s answer to ** suggests the component perpendicular to the radial direction might be called normal velocity.
Question: How can the tangential velocity of an elliptical Kepler orbit not be tangent to the orbit, but instead be perpendicular to the radial component? Help me Mr. Wizzard!