a set of narrow pieces of leather and metal pieces that is put around the head and body of an animal, especially a horse, so that the animal can be controlled and fastened to a carriage, etc.

a set of straps(= long narrow pieces of a strong material) for fastening something to a person’s body or to keep them from moving off or falling

She fastened the safety harness tightly around her waist before starting the descent.

to put a harness on a horse or other animal; to attach a horse or other animal to something with a harness

to control and use the force or strength of something to produce power or to achieve something

attempts to harness the sun’s rays as a source of energy

We must harness the skill and creativity of our workforce.

How can this energy be harnessed effectively for the good of humankind?

They are attempting to harness the power of the sun.

LEARNit Dictionary