Fanatic means the same as fanatical.
fanatics
If you describe someone as a fanatic, you disapprove of them because you consider their behaviour or opinions to be very extreme, for example, in the way they support particular religious or political ideas.
I am not a religious fanatic but I am a Christian.
我不是个宗教狂热分子,但我是个基督徒。
If you say that someone is a fanatic, you mean that they are very enthusiastic about a particular activity, sport, or way of life.
Both Rod and Phil are football fanatics.
罗德和菲尔两人都是足球迷。