top something/somebody ↔ up phrasal verb especially British English ( see also ↑ top )
1 . to add more liquid to a container that is partly full:
I’ll just top up the coffee pot.
2 . to put more drink in someone’s glass or cup after they have drunk some:
Can I top you up?
3 . to increase the level of something slightly so as to bring it back to the level you want:
He had to do extra jobs at the weekend to top up his income.
⇨ ↑ top-up