"Let drop" is a phrase that typically means to reveal or disclose information that was previously unknown or secret. However, there are several synonyms that can be used in its place. One alternative is to "spill the beans," which means to divulge a secret. Another synonym is "blurt out," which implies revealing information unintentionally or impulsively. Additionally, the phrases "let slip" or "give away" can also be used to indicate an inadvertent revelation of information. Overall, there are numerous options to choose from when looking for synonyms for "let drop," each with their own unique connotations and implications.