What does the word blue mean?

Usage examples for blue

  1. There was no one up about the cabin except the officers of the boat, and as we never tried to win their money, things looked a little blue for any business before morning, unless some of the passengers could be got up. – Forty Years a Gambler on the Mississippi by George H. Devol
  2. " Time enough to be blue and all put out when you have utterly failed," Ree exclaimed one day. – Far Past the Frontier by James A. Braden