Second is acceleration.
Third is jerk.
Well done! I did have it explained to my forgetful self upthread a bit... this is SO embarrassing, as I know I learned and used the term in my college courses (physics major), but all it does now is ring a faint bell. And to think that I used to revel in mechanics... well, it WAS the early 70's -- I suppose there's a reason I don't remember it better.
Well, thank you for both your patient explanation and your excellent joke! A very Happy New Year to you and ctdonath2.