fa ‧ nat ‧ ic /fəˈnætɪk/ BrE AmE noun [countable]
[ Date: 1500-1600 ; Language: Latin ; Origin: fanaticus 'made wild or mad by the gods' , from fanum 'religious building' ]
1 . someone who has extreme political or religious ideas and is often dangerous SYN extremist :
fanatics who represent a real danger to democracy
a religious fanatic
2 . someone who likes a particular thing or activity very much SYN enthusiast :
a health food fanatic
a fitness fanatic
—fanatical adjective :
a fanatical sportsman
He was fanatical about tidiness.
—fanatically /-kli/ adverb