A charm that cheers a person up, makes them happy.
History and Notes
Invented by Felix Summerbee during the 1400s (FW).
References from the canon
Cheering Charms were part of the Charms curriculum for the third-years. They were included in the final exam for that term (PA15).
Cheering Charms were part of the written Charms O.W.L. exam. Hermione worried that she hadn't written enough about them, but since she was considering including the countercharm for hiccups as part of her answer, it seems likely that she wrote more than plenty (OP31).