Cult

a particular system of religious worship, especially with reference to its rites and ceremonies.
an instance of great veneration of a person, ideal, or thing, especially as manifested by a body of admirers:
the physical fitness cult.
the object of such devotion.
a group or sect bound together by veneration of the same thing, person, ideal, etc.
Sociology. a group having a sacred ideology and a set of rites centering around their sacred symbols.
a religion or sect considered to be false, unorthodox, or extremist, with members often living outside of conventional society under the direction of a charismatic leader.
the members of such a religion or sect.
any system for treating human sickness that originated by a person usually claiming to have sole insight into the nature of disease, and that employs methods regarded as unorthodox or unscientific.
of or relating to a cult.
of, for, or attracting a small group of devotees:
a cult movie.
Contemporary Examples

Yes, which leads me to a fascination with the cult leader, which is in a way what Skilling was at ENRON.
Ken Lay Lives! Kevin Sessums April 25, 2010

But the inevitable cult of apology is of course provoked by the cult of outrage.
Too Late To ‘Pologize For NSA Revenge Porn Leak Lizzie Crocker June 27, 2014

This cult classic Vin Diesel clip from a British talk show is great for a number of reasons.
Vin Diesel’s 6 Greatest YouTube Masterpieces Amy Zimmerman January 28, 2014

A lot of people thought Audrey was doomed and linked to the cult.
True Detective’s Red Herring: Actress Erin Moriarty, Who Plays Marty’s Daughter, Tells All Marlow Stern March 9, 2014

And today, intellectual property enjoys a kind of cult status.
Tesla’s Radical Patent Move is a Plot to Take Over the Road Daniel Gross June 14, 2014

Historical Examples

The cult of the Nation is the professionalism of the people.
Creative Unity Rabindranath Tagore

Here in Rome on every side was to be found the cult of the Beautiful.
The Prodigal Returns Lilian Staveley

In a sense, the cult of the sea is the oldest note in English literature.
English Literature: Modern G. H. Mair

I am impelled by no fanatical zeal, and have no creed or cult of my own to vindicate.
Lippincott’s Magazine, September, 1885 Various

Such a cult must direct itself particularly to the teaching of the young.
The Salvaging Of Civilisation H. G. (Herbert George) Wells

noun
a specific system of religious worship, esp with reference to its rites and deity
a sect devoted to such a system
a quasi-religious organization using devious psychological techniques to gain and control adherents
(sociol) a group having an exclusive ideology and ritual practices centred on sacred symbols, esp one characterized by lack of organizational structure
intense interest in and devotion to a person, idea, or activity: the cult of yoga
the person, idea, etc, arousing such devotion

something regarded as fashionable or significant by a particular group
(as modifier): a cult show

(modifier) of, relating to, or characteristic of a cult or cults: a cult figure
n.

1610s, “worship,” also “a particular form of worship,” from French culte (17c.), from Latin cultus “care, labor; cultivation, culture; worship, reverence,” originally “tended, cultivated,” past participle of colere “to till” (see colony). Rare after 17c.; revived mid-19c. with reference to ancient or primitive rituals. Meaning “devotion to a person or thing” is from 1829.

Cult. An organized group of people, religious or not, with whom you disagree. [Rawson]

In anthropology, an organization for the conduct of ritual, magical, or other religious observances. Many so-called primitive tribes, for example, have ancestor cults, in which dead ancestors are considered divine and activities are organized to respect their memory and invoke their aid. A cult is also a religious group held together by a dominant, often charismatic individual, or by the worship of a divinity, an idol, or some other object. (See animism, fetish, and totemism.)

Note: The term cult often suggests extreme beliefs and bizarre behavior.