In the novel "Brave New World" by Aldous Huxley, the word 'pneumatic' was used to describe the sensation of sex with the main female character Lenina. In this context it means well rounded, or bouncy, in reference to her breasts and her body.
Lenina is quite pneumatic.... *pats Lenina's leg*
A clever way to call someone an airhead (playing off the traditional meaning of pneumatic, which is, "pertaining to or filled with air.") Usually used in reference to women who are bubbly and nice, but dumb as a box of rocks.
Girl 1: That girl is such an idiot--she probably can't remember how to spell her own name.
Girl 2: Be nice, she's just a little....pneumatic.
Pneumatics utilizes the same theories that hydraulics do, but instead of using oil, it uses compressed air to propel its movements. As of late pnematics has been an increasingly popular in implementation with various eastern european forms of bondage - ask your nearest kinky (sexually starved) engineering student about it.
Person (who finds great delight in pointing out the rather obvious) A: Woah! Check out that super-awesome brakes on that truck/train!
Person (who recites basic knowledge available to the general public through the uses of Wikipedia) B: Oh yea - that's an example of pneumatics at work.
The word you know how to spell because you watched "Neither a Borrower Nor a Speller Bee" (The Suite Life of Zack and Cody: Season 2, Episode 12) so much.