1 also freshen up [transitive]
to make something look or feel clean, new, attractive, cool etc [= brighten (up)]:
I'm going to buy some white paint to freshen up the bathroom walls.
if the wind freshens, it gets colder and stronger
3 also freshen up [transitive]
to add more liquid to a drink:
The waitress freshened our coffee.
freshen upphrasal verb
freshen yourself up
Fiona's gone to freshen herself up.