What exactly rotates along the lateral axis? Is 'rotate' mathematically correct? Researching the etymology of 'rotate' (that OED lacks!), I chanced on Anas Maaz's Quora answer:


  What many does not know is 'rotate' is just not a fancy word, but it involves a real physical rotation. When Rotation speed (Vr) is reached, the pilot pulls the control column which deflects the horizontal stabilizer, causing a rotation along the lateral axis of the airplane lifting up the nose wheel.



Am I correct that Maaz's referring to the 'lateral axis' in the diagram beneath?





Even if yes, what exactly ROTATES? How does the lateral axis ROTATE?


Imagine the wing on the y-axis and time on the x-axis, like the graph beneath. 
I don't think it's correct mathematically to state that an axis rotates, when it's the function that moves up as time passes?
Yes that is the lateral axis of the aircraft.
The aeroplane rotates about the lateral axis, causing the nose to go up/down. The aeroplane then descends or climbs, causing the aeroplane axes to shift relative to earth axes. But the aeroplane axes are all defined relative to the aeroplane.