1TD [intransitive and transitive]TD
to make a computer, machine, or piece of software better and able to do more things
upgrade (something) to something
You'll need to upgrade your hard drive to 4Mb before running this software.
to improve something and make it more modern, especially in order to provide a better service:
The hotel has recently been refurbished and upgraded.
3 [intransitive and transitive]TTA
to give someone a better seat on a plane or a better room in a hotel than the one they paid for
upgrade (somebody) to something
We can upgrade you to business class.
to give someone a more important job
to change the official description of something to make it seem better or more important [≠ downgrade]
upgrade something to something
Four of the regions were upgraded to the status of republic.
to learn new and more modern ways of doing a particular job
—upgrade noun [countable]