Pestkanker is a Dutch swear word that literally combines pest, meaning plague, with kanker, meaning cancer, and Dutch speakers use it as a strong insult rather than a literal medical reference. Because Dutch swearing often draws on disease terms, the word carries a shocking tone that stands out to both native speakers and international meme audiences. Online it circulates as a short reaction clip in Dutch-language memes, gaming videos and reaction edits, where its harsh sound does most of the work. Its continued use comes from that instant, recognisable aggression, not from any single viral video or celebrity moment.