There are several synonyms for the phrase "like crazy," which is typically used to express something that is happening intensely or with great fervor. Some examples of synonyms for this phrase include "frantically," "wildly," "heavily," "madly," and "intensely." These words are all used to convey a sense of urgency or intensity, and can be used interchangeably with "like crazy" in many contexts. Whether you are describing an emotional reaction, physical activity, or any other kind of intense experience, these synonyms can help you to communicate your meaning clearly and effectively, without resorting to repetitive or cliched language.