Clam up definitions

Clam up

1) Become silent 2) Get quiet 3) Give nothing away 4) Go quiet 5) Keep mum 6) Not rat 7) Play dumb 8) Quit talking 9) Refuse to speak 10) Refuse to talk 11) Refuse to testify 12) Stop talking 13) Suddenly be quiet 14) Withhold information
Found on https://www.crosswordclues.com/clue/clam-up

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Clam Up

Clam up is slang for to keep quiet, to refuse to talk.
Found on http://www.probertencyclopaedia.com/browse/ZC.HTM

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