enthusiast, n. [http://oed.com/view/Entry/62880] 3.a. One who is full of "enthusiasm" for a cause or principle, or who enters with enthusiasm into a pursuit. (see enthusiasm n. 3) enthusiasm, n. [http://oed.com/view/Entry/62879] 3.a. Rapturous intensity of feeling in favour of a person, principle, cause, etc.; passionate eagerness in any pursuit, proceeding from an intense conviction of the worthiness of the object. |
See also: http://www.stuartburch.com/03-blog/enthusiast