Question

Can we say that an object is at absolute rest?

Answer 1

Nothing is at absolute rest or in absolute motion.

Lets take an example:

If you are sitting in the bus which is moving, In bus's reference you are at rest and in earth's reference you are moving. So nothing is at absolute rest and at absolute motion.

If you are standing on the ground then you are at rest in earth's frame but you are moving in sun's frame as earth is moving around the sun and you are also moving with earth.