1. [techspeak] To transfer programs or data over a digital communications link from a smaller or peripheral `client' system to a larger or central `host' one. A transfer in the other direction is, of course, called a download
(but see the note about ground-to-space comm under that entry).
2. [jargon] To send data (especially large relatively standalone pieces of data like files and images) over the wire to a remote location.
3. [speculatively] To move the essential patterns and algorithms that make up one's mind from one's brain into a computer. Those who are convinced that such patterns and algorithms capture the complete essence of the self view this prospect with pleasant anticipation.