keep mum keep in line • keep note · · · Info · Definitions · Synonyms · Characters · · keep mum · · Text Common · · Latin · · Scripts 8 · · Length 2 · · Syllables Definitions · · · (verb) refuse to talk or stop talking; fall silent. Synonyms: close up, clam up, dummy up, shut up, belt up, button up, be quiet, keep mum. Example: "The children shut up when their father approached." · · Verb Definition 1 Synonyms · · · close up · · Synonym 1 clam up · · Synonym 2 dummy up · · Synonym 3 shut up · · Synonym 4 belt up · · Synonym 5 button up · · Synonym 6 be quiet · · Synonym 7 Characters · · space U+0020 e latin small letter e U+0065 k latin small letter k U+006B m latin small letter m U+006D p latin small letter p U+0070 u latin small letter u U+0075