How would you define a cult?
You asked an excellent question and one that we must all be extremely careful of dubbing "a cult."
There are good cults and bad. A good cult could be a religious one, yet some Christians will consider Jehovah Witness a cult and have labeled them as preying on the weak. When someone labels such a thing it is usually because of the lack of understanding.
Good cults are usually a small group of people that can have a cult in most anything. A belief system on a certain subject perhaps or a religion (Yoga, regime of exercising, etc.). For instance: Our Christian beliefs could be considered a cult in the eyes of those in India while we feel that because they may not be Christians in our eyes they are the cult. It gets complicated!
Witchcraft has come under the heading of a bad cult simply because many don't realize the significance of this particular belief and believe it's all "bubble, eyeballs, rats and toil." Believe it or not there are good witches (so called by society) that are actually nothing more than great healers for their fellow man. I've seen it myself where a person would call someone such as a healer a witch (because the person may act odd or give some special herbs and live in a lonely out-of-the-way place call them a witch) yet these same people will sneak off to see this so-called witch for help when conventional medicine has let them down. There is certainly some evil with certain sects (or cults) of Witchcraft and those are ones that want power and mean to do harm to others, such as casting spells or putting the seed into a particular individual that they have cast a spell on them to do them harm.
We often refer to "cult movies" or "cult classics" and it only means that these movies have remained a favorite of a group of people. The term "cult" has been misused. The word "cult" comes from the French "cult" which is from the Latin word "cultus" (care/adoration) and Latin "Colere" (to cultivate.) So, we can plant seeds of good or bad.
You can have political cults such as "sit ins" during the Vietnam War. They disagree with war so the country is split. This does not mean it's bad. After all the U.S. and Canada have the freedom of speech! Yet, some called the Black Panthers a powerful and controlling cult.
Mental Health Groups are a cult in their own when psychiatrists meet to discuss new technology, but when groups meet such as "doomsday cults" or scientists secretly meeting for "mind control testing" (which was true during the 2nd World War) this is a cult against society as a whole.
Bad cults are simply groups (small or large) that are either ignorant because they are afraid of something different, or someone that has decided they want to become powerful and have a following such as Jonestown and Charles Manson. The KKK is considered a cult and once had millions of followers, but has dwindled since. To those that attended the KKK meetings and the society in which they were brought up they felt they spoke for the whole of the U.S. and Canada (oh yes, Canada also had the KKK.) When anything harms another out of fear or wanting power it becomes a dangerous cult. Cult leaders are often crafty, mind-benders and Jonestown is a prime example as is Charles Manson. It's when one or more people can make you doubt (in a group) what is right and what is wrong. Often they will use religion to bait you in as prey, but eventually the scene becomes ugly and sometimes it's difficult to get out of such a cult.
Cults were hot and heavy in the 1960s. Gurus (some good, some bad) swept away the children of unsuspecting parents and often the Cult was so powerful parents would have to hire specialists to kidnap their own children and then have to go through the unpleasant task of letting the specialists unbrain-wash their kids. It was a terrible time. It was the time also of "Killer Cults." The so-called leaders were egomaniacal and pit themselves against the beliefs of the church and the world as a whole. They were so-called visionaries and drunk with power. They were self-proclaimed individuals and usually used massive amounts of weapons before the day of reckoning.
It's best not to use the word "cult" if it's a well-meaning and harmless group of people. It ties them into what the evil wrong-doers of cults are really all about.
THE TERM CULT COMES FROM A GREEK WORD THAT MEANS SYSTEM OF BELIEVES OR RELIGION.
IE EVERY RELIGION IN THE ENTIRE WORLD IS A CULT
PEOPLE NOW SEE THE WORD CULT AND BELIEVE THAT IT MEANS JIM JONES OR SOME CRAZY ORGANIZATION THAT END UP DOING MASS SUICIDE. BUT IN REALITY
ALL A CULT IS IS A SYSTEM OF BELIEFS
IN ANCIENT GREECE PEOPLE WHO WORSHIPED IN ONE RELIGION WOULD IDENTIFY THEMSELFS AS A WORSHIPER OR MEMBER OF A CULT IE THEY MIGHT SAY THEY BELONG TO THE CULT OF ZEUS OR THE CULT OF HERA OR THE CULT OF ARES ETC ETC
THAT IS ALL THE WORD CULT MEANS ITS SIMPLY A GREEK WORD THAT MEANS SYSTEM OF BELIEFS