Mesmerism is essentially the same as hypnosis, the word mesmerism is just a lot older than hypnosis, and was packed with substantial misconceptions in the time it was used, which was the reason to change it. Mesmerism comes from the last name of Franz Anton Mesmer, he was the first to practice what we would call hypnosis today. Mesmer had his own ideas about what he was doing, he thought that it was some kind of animal magnetism that he possessed that enabled him to cure some people of their sufferings. At that time aswell as today there were a lot of skeptical people, this skepticism led the king of France to appoint four people to investigate if Mesmer had made a discovery of physical character within the body (Among those four was the american ambassedor Benjamin Franklin). The group found that benefits of mesmerism could only be attributed to imagination.

Mesmer did succesfully treat some of the people who seeked out his help. But his theory about why it worked didn't really have any substance. This led James Braid to find a new word that could better describe the phenomenon, and thereby coining a term unassociated with Franz Anton Mesmer. The new word was "hypnotism". It is derived from Greek mythology where Hypnos is the God of sleep. This leads me to conclude that mesmerism and to be mesmerized is the same as hypnosis and to be hypnotized.