What does the word wager mean?

Usage examples for wager

  1. He followed me, and I wager he is standing without longing to know if the king is really eating his bread." – Berlin and Sans-Souci by Louise Muhlbach
  2. I must win my wager! – The Man Who Rose Again by Joseph Hocking
  3. I wondered at the start that there was so much furniture in it, and I'll wager there are things hidden beneath the bed and back of that large screen. – The Gray Mask by Wadsworth Camp