The antonyms for the phrase "made happen" are numerous, and include words such as prevent, thwart, hinder, obstruct, impede, and hinder. These words denote the opposite of making something happen, as they all refer to the act of actively preventing something from occurring or stopping it from occurring altogether. Other antonyms for "made happen" might include words such as stifle, neutralize, counteract, and suppress, which all imply an active effort to counter or negate the effects of some action or event. Regardless of the specific words used, the antonyms for "made happen" all have one thing in common: they describe actions that actively work against the process of creating change or bringing about a particular outcome.