also up-grade, 1847, "upward slope," from up (adj.) + grade (n.). The meaning "upgraded version" is recorded from 1980.
"increase to a higher grade or rank," 1904 (transitive); 1950 (intransitive), from up (adv.) + grade (v.). Related: Upgraded; upgrading.
I got an upgrade to first class when coach class was full
the power plant received a new upgrade
The company upgraded their personnel
I've upgraded my computer so I can run better software
I upgraded to First Class when Coach Class was overbooked
The airline upgraded me when I arrived late and Coach Class was full