What is the meaning of the word "jettison"?

Definitions:

  1. to drop or throw something, as from a ship or airplane copy to clipboard verb
    • We decided to jettison the fish we caught yesterday, since we forgot to refrigerate them. copy to clipboard
  2. to throw away something causing an unnecessary encumbrance copy to clipboard verb
    • It's time to jettison those outdated ideas. copy to clipboard