"Laugh head off" is an expression used to describe a hearty and uncontrollable bout of laughter. There are several other synonyms that can be used in place of this phrase, including "crack up," "burst out laughing," "giggle uncontrollably," and "roar with laughter." In addition, one could say that they "doubled over with laughter" or "found something hilarious." These synonyms can be used interchangeably to describe the same experience and are perfect for conveying the sense of joy and amusement that comes with a good laugh. Whether it's a funny joke or an amusing situation, there is nothing quite like laughing your head off.