Source : WordNet®

perk up
     v 1: gain or regain energy; "I picked up after a nap" [syn: {perk},
           {percolate}, {pick up}, {gain vigor}]
     2: cause to be alert and energetic; "Coffee and tea stimulate
        me"; "This herbal infusion doesn't stimulate" [syn: {stimulate},
         {arouse}, {brace}, {energize}, {energise}] [ant: {de-energize},
         {de-energize}, {sedate}]