Meet one's Waterloo is an idiomatic expression that describes the moment when someone experiences a final defeat or setback. If you want to express the same idea in a different way, you can use a variety of synonyms. For instance, you can say "reaching a dead end", "hitting a brick wall", "coming to grief", or "meeting one's match". Other synonyms for meet one's Waterloo include "bite the dust", "suffer a defeat", "get one's comeuppance", or "fall from grace". Whether you're talking about a personal challenge or a professional setback, using the right synonym can help you convey your message clearly and effectively.