10. Cheer, gladden, enliven mean to make happy or lively. To cheer is to comfort, to restore hope and cheerfulness to (now often cheer up, when thoroughness, a definite time, or a particular point in the action is referred to): to cheer a sick person; She soon cheered him up. To gladden does not imply a state of sadness to begin with, but suggests bringing pleasure or happiness to someone: to gladden someone's heart with good news. Enliven suggests bringing vivacity and liveliness: to enliven a dull evening, a party.

Did you mean cheerio?