- Surgery on any part of the nervous system, especially the brain; neurosurgery.
- (uncountable, idiomatic) Something that is overly complex, detailed or confusing.
- It's not brain surgery. Just screw in the bulb and flip the switch.
- This phrase is usually used in a negative comparison, as in the example above, to show that something is (or should be) simple, straightforward, or obvious.
- (something complex and confusing): rocket science