buck up phrasal verb ( see also ↑ buck )
1 . to become happier, or to make someone happier:
Come on, buck up, things aren’t that bad!
buck somebody ↔ up
You need something to buck you up.
2 . buck up! British English old-fashioned used to tell someone to hurry up:
Buck up, John! We’ll be late.
3 . informal to improve, or to make something improve:
It’ll be a long time before the situation starts to buck up.
buck something ↔ up
a company that is looking to buck up its networking capabilities
4 . buck your ideas up British English informal used to tell someone to improve their behaviour or attitude