The phrase "the elephant in the room" is commonly used to describe an issue or problem that everyone is aware of but no one wants to address. There are several synonyms that can be used to convey the same meaning, such as "the 800-pound gorilla," "the big issue," "the forbidden topic," "the unspoken truth," and "the taboo subject." These phrases all suggest that there is an obvious problem or issue that is being ignored or avoided. Using any of these synonyms can help to draw attention to the problem and encourage people to confront it, rather than ignoring it and allowing it to persist.