The crossword solution for the term 'fanatical fan' is 'ZEALOT'. A ZEALOT is an individual who is extremely passionate and devoted to a cause or belief. They are often willing to go to extreme lengths to defend their beliefs, even if it means sacrificing their own safety or comfort. Zealots are often seen as fanatical in their devotion to their cause, which is why this term is used to describe a fanatical fan.