Is the biggest object in the universe weightless?

"If weight is the gravitational force exerted on an object by the nearest most massive body"

Weight is the felt effect of gravity.

Gravity is not based on only the nearest, or most massive body. Gravity is a force that all objects with mass exert on all other objects with mass.

You seem to think that only a more massive body would exert gravity on a less massive one, but that's completely wrong.

Each individual particle in the universe that has mass exerts a gravitational pull on every other particle. That would be as true for the particles in this putative most massive body as for any others.

"since nothing can exert a gravitational force on it"

In fact, everything would exert a gravitational force on it.

Biggest Object In The Universe

You might need to rephrase your question.

In asking your question you have forgotten that the most massive body can exert its own gravitational force upon itself.

The most heavy objects are neutron stars. One teaspoon of that would weigh about ten tons.

Galaxies are huge, and they rotate so as they rotate, they spin like a top and thus they have a shape like a flattish whorl.

Because of centrifugal force, they don't collapse upon themselves.

When the balance of gravity is overcome, an implosion takes place causing the "neutron star" to become a "Black Hole"

If you look up wikipeadia for Black Hole and see how they are formed, you would get an idea of what "gravity"can do.

So the biggest objects in the Universe are, rather balanced as they float around and exist because of centrifugal force. But they are not weightless, rather the opposite, they are, extremely massive.

Gravity is only relevant to the mass and its orbit and proximity to the nearest star, even the most distant of galaxies exert a gravitational force on all objects within the cosmic plane no matter how miniscule the force, it is still there.

If weight is calculated merly in units of weight, measured within it gravitational pull, Then yes. If we are failing to see a higher Realm of measurement, simply because we cannot see or feel it, Then size as we see it, Should break all those laws therefor rendering the bigger heavier.

Gravity is the bending of spacetime by matter. So the answer is No. Gravity is a effect of matter on spacetime. It is there irrespective of external matter/bodies near or otherwise.

Yes

if the mass is to great even time n light cannot escape its pull-so how could you answer this if you can never see this object if it does not even exist in our time