noun
a person who manifests extreme and often uncritical ardor, fervor, or devotion in an attachment
an increasing number of ecology enthusiasts
Synonyms: bigot, bug, fanatic, fiend, freak, maniac, nut, zealot
Related Word: addict, aficionado, buff, bum, devotee, fan, habitué, lover, votary; partisan, supporter; bear, extremist
Contrasted words: depreciator, detractor, disparager, knocker