Wikipedia
Barophobia
Barophobia is the irrational fear of gravity, a type of specific phobia. Individuals suffering from barophobia can either have the fear that gravity might crush them, the fear of falling because of the gravity involved (distinct from the fear of heights), or even the fear that gravity might cease to exist and they will float away.
The word barophobia comes from the Greek , -baros, meaning "weight" and - phóbos, meaning "fear".