When we are asked to keep quiet, we often have different ways to convey that message. Some might say "hush" or "shush" to indicate silence. Others may opt for "be silent" or "keep mum" as substituted phrases. "Mute," "wordless," and "silent" are other synonyms that represent the same idea of being quiet. One may also say "zip it" or "button it" to emphasize the need to keep quiet. Some other common phrases for this purpose are "keep a lid on it," "clam up," and "not a peep." In summary, while "keep quiet" is a straightforward phrase, there are many different synonyms to choose from when we want someone to remain silent.