perk2 [intransitive and transitive]
to percolate (3)
perk upphrasal verb
to become more cheerful, active, and interested in what is happening around you, or to make someone feel this way:
She seemed kind of tired, but she perked up when Helen came over.
perk somebody ↔ up
There's no doubt coffee perks you up.
to become more active, more interesting, more attractive etc, or to make something do this
perk something ↔ up
A little chili will perk up the sauce.