What does the word sustain mean?

Usage examples for sustain

  1. You surely would not dare say what you have, unless certain my father would sustain you. – Love Under Fire by Randall Parrish
  2. Necessary as this measure is to sustain the honor and the interests of the country engaged in a foreign war, it is not doubted but that Congress will promptly authorize it. – Complete State of the Union Addresses from 1790 to the Present by Various
  3. But don't you need any outside element to sustain life? – The Giants From Outer Space by Geoff St. Reynard