What does the word boot mean?

Usage examples for boot

  1. If they're willing to throw some good money after bad, they can get it back, and a handsome profit to boot. – Space Viking by Henry Beam Piper
  2. " The boot can wait. – Furze the Cruel by John Trevena
  3. I used to open my door and fling a boot at it; but that only served for a time. – Macleod of Dare by William Black