1
general::
Phrase(s): cheer up
[for a sad person] to become happy. • After a while, she began to cheer up and smile more. • Cheer up! Things could be worse., Phrase(s): cheer someone up
to make a sad person happy. • When Bill was sick, Ann tried to cheer him up by reading to him. • Interest rates went up, and that cheered up all the bankers.
McGrawhill's American Idioms And Phrasal Verbs
2
general::
Become or make happy, raise the spirits of, as in This fine weather should cheer you up. This term may Also be used as an imperative, as Shakespeare did (2 Henry IV, 4:4): "My sovereign lord, cheer up yourself." [Late 1500s]
American Heritage Idioms