"Showed once and for all" is an idiomatic expression that indicates a definitive and conclusive demonstration or proof of something, leaving no room for doubt or further discussion. The phrase is typically used to highlight that a particular action, event, or situation has decisively settled an argument, debate, or question.
When someone "shows once and for all," they provide clear evidence or examples that effectively settle an issue or confirm a belief. This demonstration is often deemed final, leaving little possibility for further dispute or contradiction. The adverb "once" emphasizes that the occasion was a singular and undeniable demonstration, while "for all" means it applies universally and comprehensively, leaving no loopholes or exceptions.
For instance, in a scientific experiment, if a researcher successfully demonstrates a theory through objective and reproducible evidence, it can be said that they have "showed once and for all" that the theory is valid, ultimately silencing any skepticism or opposing viewpoints.
The phrase can also be used in everyday situations or conversations to express the finality of an action or decision. For instance, if someone consistently proves their competence or reliability in a particular field or task, they might "show once and for all" that they are the best choice for a particular role or responsibility, eliminating any doubts or contestations.
