white flag, show the

show a/the white flag

To offer a sign of surrender or defeat; to yield or give in. After the prosecutors brought forward their newest evidence, the defendant showed the white flag and agreed to the plea bargain. We've been in negotiations for weeks, but it looks like the other company might finally be ready to show a white flag.
See also: flag, show, white
Farlex Dictionary of Idioms.

white flag, show the

Also, hang out or hoist the white flag . Surrender, yield, as in Our opponents held all the cards tonight, so we showed the white flag and left early. This expression alludes to the white flag indicating a surrender in battle, a custom apparently dating from Roman times and adopted as an international symbol of surrender or truce. [Late 1600s]
See also: show, white
The American Heritage® Dictionary of Idioms by Christine Ammer.
See also:
  • show a/the white flag
  • hoist a/the white flag
  • wave a/the white flag
  • rule on
  • rule on (something)
  • open and shut
  • open-and-shut
  • build a case against (someone or something)
  • gather a case against (someone or something)
  • come to a/the conclusion