Other forms: hypnotisms
The act of putting someone into a hypnotic trance is called hypnotism, and it's usually done by a hypnotist.
Some doctors use hypnotism to help patients break bad habits and addictions like smoking. There are also hypnotists who work as entertainers, using hypnotism to put volunteers into mesmerized states and then suggesting they do silly things to make the audience laugh. The original term was neuro-hypnotism, coined in 1842 by Dr. James Braid, who was an early researcher and practitioner of hypnotism.