Backside
A spin where the rider rotates with the back of their body towards the direction of travel first. For example, if you are riding in a normal stance with your right foot forward, an anticlockwise rotation will be a "backside rotation."
Backside rotations are often times mistakenly referred to as blindside spins.

Baller
This is a term used for when a rider does the handle pass of their spin by passing the bar between their legs.

Flatline Spin
A spin where the rider goes over their lines instead of passing the bar.

Frontside
A spin where the rider rotates with the front of their body towards the direction of travel first. Eg: In the normal stance with the right foot forward, rotating clockwise.

Off-Axis
When a rider does a spin but goes off the vertical axis so the board usually gets up to shoulder level or above

Osmosis
When the rider performs a spin by tossing the bar from one hand to the same hand again, bypassing the other hand.
A spin where the rider does a shifty one way, then back the other, then spins back in the direction of their initial shifty.

Shifty
Board is shifted 90 degrees in one direction and then shifted back in the opposite direction

To Blind
The rider lands with the bar around their back instead of passing the bar

Backside, back towards the kite first? Frontside, front towards the kite first? But when you initiate the jump, and thus the spin, the kite is usually above or slightly behind you (unless you popping off a wave, or just popping by edging upwind slightly), therefore your explanations are a bit misleading.

Also, with the kite in front of you, low or high, no matter, unless you are riding toeside, any spin, in any direction, will have you back facing the kite after the first 180 deg, so this does not describe it either, unless you mean that backside is when riding regular and frontside is when riding toeside???!

For true back and front side explanations, you have to go back to wave surfing, skating or snowboarding... Coming up the face of the wave / ramp / pipe, and then turning so your back and heels are facing the wave / ramp / pipe, more than your front and toes, is backside. Continuing this motion to launch out of the lip / coping / lip with your back and heels facing the lip / coping / lip with a rotation up to 180 degs, to return to the wave / ramp / pipe going forwards will be a backside air.

Coming up the face of the wave / ramp / pipe, with your front and toes facing the wave / ramp / pipe is frontside... and the rest is self explanatory.

The only way to really explain frontside and backside spins in kiting is by using the direction of movement. i.e. Riding normally, when the right foot is the leading foot spinning clockwise is frontside, while anti-clockwise is backside.
Riding normally, when the left foot is the leading foot spinning clockwise is backside, while anti-clockwise is frontside.
Visualise it for all the boardsports that I mentioned and you will see that I am right.

Yeah, point taken bigsmelly. My explanation is still legit however... Your kite position can still give the basis for backside and frontside - the kite is pulling you in one direction right up until the point of sending it. Unless you do a transition, your kite will return to its original direction of pull. So it is still legit to use the kite's position as the basis for frontside/backside orientation.

Not really, cause any spin, in any direction, will have your back facing the kite after the first 180 deg.

Point taken BigSmell. My explanations were confusing. In light of your criticisms, I've modified the explanations.

I understand your definitions, but if that's so, a beginner trick, commonly referred to a "backroll" is actually a frontside roatation?

trying to figure it out...
B.

a back roll is a rotation on a horizontal axis were a spin is a vertical axis so a back roll is still a back roll.

If you think about it - A backrool is a off axis frontside 270 - Am I wrong?

Do you define clock references looking at the rider from above? If so, then you definitions are incorrect. When the right foot is the leading foot and you are spinning counter-clockwise (looking from above), it is the front spin and vice versa.