Question

What is arbitrary motion

Answer 1

Arbitrary direction means that direction which is taken without any reason.
For example while explaining _ Null vector it is defined as magnitude zero and arbitrary direction.
Therefore simply a quantity with zero magnitude can have arbitrary direction.

Answer 2

first arbitrary is not motion ,

it means that direction which is taken without any reason.

For example Null vector it is defined as magnitude zero and arbitrary direction. simple quantity with zero magnitude can have arbitrary direction