The phrase "say nothing" can be replaced by a variety of synonyms depending on the context. These include "keep silent," "remain quiet," "opt for silence," "stay mum," "hold one's tongue," "keep one's mouth shut," "zip it," and "button one's lips." These synonyms convey the same idea of choosing not to speak or express oneself, either to avoid revealing information or to indicate disapproval or indifference. Each of these phrases may be used in different situations, from a request for confidentiality to a refusal to engage in idle gossip or rumor-mongering.