1.
If you freshen something up, you make it clean and pleasant in appearance or smell.
A thorough brushing helps to ~ your mouth...
My room needed a lick of paint to freshen it up.
PHRASAL VERB: V P n (not pron), V n P
2.
If you ~, you wash your hands and face and make yourself look neat and tidy.
After Martine had freshened up, they went for a long walk.
PHRASAL VERB: V P