What is the meaning of the word "upgrade"?

Definitions:

  1. a reservation that is improved copy to clipboard noun
    • I got an upgrade to first class when coach class was full copy to clipboard
  2. get better travel conditions copy to clipboard verb
    • I upgraded to First Class when Coach Class was overbooked copy to clipboard
  3. give better travel conditions to copy to clipboard verb
    • The airline upgraded me when I arrived late and Coach Class was full copy to clipboard
  4. the act of improving something (especially machinery) by raising it to a higher grade (as by adding or replacing components) copy to clipboard noun
    • the power plant received a new upgrade copy to clipboard
  5. to improve what was old or outdated copy to clipboard verb
    • I've upgraded my computer so I can run better software copy to clipboard

Synonyms: