In the tucking case for these designs it's the point where the overall pitch forces swap direction from wanting to move nose up to wanting to go nose down. As you know "normal" models are flying with a CG that is trying to nose them down while the aerodynamic trim of the model is trying to rotate the model nose up. Steady level flight occurs when the moment of the CG being in front of the neutral point perfectly matches the aerodynamic trim's tendency to try to rotate the nose up. Now if the trim of the model alters and over a rather narrow speed change the trim forces switch from nose up torque to nose down torque we suddenly have a tucking issue. Apparently the unique planform of the Speedy Bee and the Great Planes Slo-Poke that I flew share this odd behaviour. I should also admit that it didn't happen like a finger snap. It actually had a small transition speed range of what I remember to be in the 5 to 7 mph range where it went from a docile easy flier to a nose tucking terror.

Like you say the terms can mix us up a lot. I'd have to go and read up on it again but I'm sort of assuming here (and we all know what happens when you assume right? ) that the pitching torque is dependent on airspeed. The faster it flies the more pitching force or torque. In all the airfoil info I've seen about pitching the value was always given as a single number like a "coefficient" and that leads me to believe that you then match that pitching moment value with the airspeed to find the rotational force of the airfoil for any given speed. I'll have to look into this aspect when I'm not so tired. I've been playing hard today and my mind is mostly mush right now.