One who aspires to be greater than an astronaught but to no aval. And or maybe possibly someone who is or is not on drugs and or way too much Star Crunch snack cakes. NOT Mr. T... Or is it? No no i dont think so. Also one who is 100% corect 34% of the time.
If you drive the X-Wing from Star Wars around the block for fun... you may be a spacetronaught.