General terms:
* Natural philosophy: This is a historical term for the study of nature, which encompasses what we now call physics.
* Science of nature: This is a broader term that includes all branches of science that study the natural world.
* Physical science: This refers to the study of matter and energy, including physics, chemistry, astronomy, and geology.
More specific terms:
* Mechanics: This is a branch of physics that deals with the motion of objects.
* Dynamics: This is a subfield of mechanics that focuses on the forces that cause motion.
* Kinematics: This is a subfield of mechanics that focuses on the description of motion.
* Electromagnetism: This is a branch of physics that deals with the interaction of electric and magnetic fields.
* Thermodynamics: This is a branch of physics that deals with heat and its relation to other forms of energy.
* Quantum mechanics: This is a branch of physics that deals with the behavior of matter at the atomic and subatomic levels.
* Astrophysics: This is a branch of physics that deals with the physical properties of celestial objects.
Ultimately, the best synonym for "physics" will depend on the specific context in which you are using it.