不声不响
bù​shēng​bù​xiǎng

silently

  1. 不 bù adverb
    not
    Negative adverb used before verbs, adjectives, and other adverbs to indicate negation; also used as a bound-form prefix to form terms with opposite meanings
  2. 声 聲 shēng noun
    sound
    sound; voice; noise; something that can be heard
  3. 不 bù adverb
    not
    Negative adverb used before verbs, adjectives, and other adverbs to indicate negation; also used as a bound-form prefix to form terms with opposite meanings
  4. 响 響 xiǎng verbnoun
    sound
    (bound form) sound; noise; echo; response.