Source : WordNet®

upgrade
     n 1: an upward slope or grade (as in a road); "the car couldn't
          make it up the rise" [syn: {ascent}, {acclivity}, {rise},
           {raise}, {climb}] [ant: {descent}]
     2: software that provides better performance than an earlier
        version did
     3: a reservation that is upgraded; "I got an upgrade to first
        class when coach class was full"
     4: the property possessed by a slope or surface that rises
        [syn: {rise}, {rising slope}]
     5: hardware that provides better performance than an earlier
        version did
     6: the act of improving something (especially machinery) by
        raising it to a higher grade (as by adding or replacing
        components); "the power plant received a new upgrade"
     v 1: rate higher; raise in value or esteem [ant: {downgrade}]
     2: to improve, especially something that was old or outdated;
        "I've upgraded my computer so I can run better software";
        "The company upgraded their personnel"
     3: give a promotion to or assign to a higher position; "John
        was kicked upstairs when a replacement was hired"; "Women
        tend not to advance in the major law firms"; "I got
        promoted after many years of hard work" [syn: {promote}, {advance},
         {kick upstairs}, {raise}, {elevate}] [ant: {demote}]
     4: get better travel conditions; "I upgraded to First Class
        when Coach Class was overbooked"
     5: give better travel conditions to; "The airline upgraded me
        when I arrived late and Coach Class was full"

Source : Free On-Line Dictionary of Computing

upgrade
     
        1. A new or better version of some {hardware} or {software}.
     
        Often used in {marketroid}-speak to mean "{bug fix}".
     
        2. The act of developing or installing a new version.
     
        (1995-03-14)