What is the term for the acceleration of gravity?

The term for the acceleration of gravity is indeed commonly referred to as "Gal." This unit specifically measures acceleration and is particularly used in the fields of geophysics and engineering. One gal is equal to 1 centimeter per second squared, which ties it directly to the concept of acceleration due to gravity.

The other terms listed, while related to physics, pertain to different concepts. Newton is a unit of force, Joule is a unit of energy, and meter per second squared is another way to express acceleration but lacks specificity to gravity in its name. In contrast, the term "Gal" provides a direct connection to the measurement of gravitational acceleration.