1. A puzzle game originating in 1987 for the Amiga computer - consisting of shuffled picture pieces of arbitrary size which needed to be shifted back to their correct places to solve the puzzle.
2. Any activity requiring concentration that is so mind-numbingly repetitive that your ability to think is adversely affected (see also above)
3. A proposition so wild, implausible or difficult that it defies comprehension. Precedes a Brain Tilt
4. A (supposedly) very difficult puzzle, riddle or problem
Brainscrambler is a puzzle game
Doing a tax return can rapidly become a brainscrambler
The global warming debate is a real brainscrambler.
Thinking about you sleeping with me is a brainscrambler.
Radio "Win a free X by solving this afternoon's brainscrambler"