fanatic

Definition of Fanatic in English :

1. fanatic, fiend

a person motivated by irrational enthusiasm (as for a cause)

Example Sentences:
'A fanatic is one who can't change his mind and won't change the subject'

marked by excessive enthusiasm for and intense devotion to a cause or idea

Example Sentences:
'rabid isolationist'

WordNet Lexical Database for English. Princeton University. 2010.

Fanatic

noun

1.

a person whose enthusiasm or zeal for something is extreme or beyond normal limits

2. informal

a person devoted to a particular hobby or pastime; fan

a jazz fanatic

adjective

3. a variant of fanatical

adjective

1.

fanatical

noun

2.

a person whose extreme zeal, piety, etc. goes beyond what is reasonable; zealot

n.

A person marked or motivated by an extreme, unreasoning enthusiasm, as for a cause.

adj.

Fanatical.