"Take the lid off" is often used figuratively to refer to revealing something, exposing the truth or discovering something that was hidden. There are several synonyms for this phrase, including "unveil," "disclose," "uncover," "reveal," and "expose." Each of these terms describes the act of bringing to light something that was previously unknown or concealed. Additionally, "unlock," "unsheathe," and "unleash" can also be used to convey a similar sense of freeing or releasing something that was previously contained or restrained. Overall, these synonyms provide a range of vocabulary options for expressing the idea of taking the lid off and revealing what lies beneath.