Noun
a body remains at rest or in motion with a constant velocity unless acted upon by an external force
Source: WordNetLike Newton's first law of motion, Einstein's theory states that if a force is applied on an object, it would deviate from a geodesic. Source: Internet
Newton's first law of motion has here been split into two parts, the first two laws. Source: Internet
The law of inertia is also known as Isaac Newton's first law of motion. Source: Internet