More the Dutch word sekte than the English word cult but he did use both of the terms See eg here The abortive birth of a destructive cult  by Frans Derks Jan M van der Lans Update IX  March  He also explained httphirrhartsemeduencycstheoryhtm the definition of a cult according to Yinger in his book Volgelingen van de goeroeFollowers of the guru  And apart from that I think that Wikipedia should explain jargon See wikipediawords to avoid Almost every person who wrote about NRMs incl Jan van der Lans first started by explaining the term NRM and comparing it to terms like sekte or cult