Implausibly is an adverb that means "in a way that is unlikely or unbelievable." There are many synonyms for implausibly depending on the situation and context in which it is used. Some of the alternatives include incredibly, unbelievably, unusually, improbably, fancifully, imaginatively, unrealistically, and far-fetched. Other synonyms for implausibly could also include absurdly, illogically, nonsensically, preposterously, ridiculously, and unfathomably. These alternatives can help add depth and variety to your writing, making it more interesting and engaging for your readers. Regardless of which synonym you choose, it's important to use it in a way that best fits the tone and meaning of your written work.