keep one's cards close to one's chest

动词 v.

英文释义

动词 v.
  1. To avoid revealing one's thoughts, circumstances, or plans. figuratively,idiomatic
    — Balthus has always kept his cards close to his chest. When I asked him if Summertime was a transcription of Poussin's Echo and Narcissus—a variant of his lost copy—he did not reply.
  2. To hold one's hand close to one's chest so that other players cannot see the cards.

词源

The figurative sense is a self-evident extension from the literal sense.
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