The word "mesmerized" refers to a state of being completely absorbed or captivated by something, and there are several synonyms that can be used to describe this feeling. "Enchanted," "spellbound," and "entranced" are all words that convey a sense of fascination or hypnotic enchantment. "Raptured," "enthralled," and "rapt" are other synonyms that can be used to describe a similar state of being totally engrossed in something. Other options include "spellbound," "awestruck," and "hypnotized." Ultimately, the choice of synonym depends on the nuances of the context in which the word is used, but all of these words capture the essence of being captivated by something beyond one's control.