A person who is devoted or earnestly committed to a particular pursuit, occupation, or subject of study. Frequently with possessive, of, or to…

A devoted admirer or loyal supporter of a person or institution. Frequently with possessive, of, or to specifying the person or institution.

A keen student or practitioner of a particular subject or discipline. Chiefly with to. Obsolete.

An amateur.

Originally: a person who intensely favours a particular cause, principle, etc., or who pursues an activity or objective with passion or zeal. Now…

A person who loves, is fond of, or has a taste for something. Frequently with of. Now rare and somewhat archaic.

A fanatical devotee of.

A person who is very enthusiastic (about a cause, an issue, etc.). Chiefly in plural.

With qualifying word or phrase: one who shows great enthusiasm for the activity, person, or thing specified, as health freak, train freak, etc.; an…

Transferred, in various senses, to persons. Used with a preceding substantive to designate a person who has a particular enthusiasm for, or interest…

A fanatic; in modern English (originally U.S.): a keen and regular spectator of a (professional) sport, originally of baseball; a regular…

A person with visionary ideas for the development or improvement of television or television programming; a person who is enthusiastic about and…

A fan or follower; (now) esp. an enthusiastic and committed supporter of a particular sport or team. Often in plural: such fans collectively.

With distinguishing word: a person characterized by a preference, liking, or affinity for a specified thing; a lover or enthusiast. Especially in…

An amateur who takes an enthusiastic interest in technologically advanced products that are intended chiefly for professionals. Frequently attributive…