To remain silent; to not say anything. (Used especially when by saying something, especially at the wrong time, one would cause trouble or difficulty for him- or herself.) Primarily heard in UK. It's better to just keep schtum when the boss starts flinging accusations than risk further incensing him.
Farlex Dictionary of Idioms. © 2015 Farlex, Inc, all rights reserved.
keep ˈschtum/ˈshtum(British English, informal) say nothing: I think we’d better keep schtum about this money, don’t you? OPPOSITE: open your (big) mouth Shtum is a Yiddish word from the German stumm, meaning ‘silent’.
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