1
: formal religious veneration : worship
2
: a system of religious beliefs and ritual; also : its body of adherents
3
: a religion regarded as unorthodox or spurious; also : its body of adherents
4
: a system for the cure of disease based on dogma set forth by its promulgator <health cults>
5
a : great devotion to a person, idea, object, movement, or work (as a film or book); especially : such devotion regarded as a literary or intellectual fad

b : the object of such devotion

c : a usually small group of people characterized by such devotion

http://www.merriam-webster.com/dictionary/cult