"As likely as not" is an idiomatic expression that means something is equally likely to happen or not. There are several other synonyms that can be used interchangeably with this phrase, such as "50-50 chance," "toss-up," "even odds," "equally probable," or "just as well as not." These phrases indicate an uncertain outcome, where there are two possible results that have an equal chance of occurring. Whether you prefer to use "as likely as not" or one of its synonyms, it's always important to choose the right language for the context to effectively convey the intended meaning.