1.
If you freshen something up , you make it clean and pleasant in appearance or smell.
A thorough brushing helps to freshen up 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 freshen up , 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