cheer

Cause (somebody) to feel happier or more cheerful.

“She tried to cheer up the disappointed child when he failed to win the spelling bee”

Become cheerful.

Give encouragement to.

Spur on or encourage especially by cheers and shouts.

“The crowd cheered the demonstrating strikers”

Show approval or good wishes by shouting.

“everybody cheered the birthday boy”

The quality of being cheerful and dispelling gloom.

“flowers added a note of cheerfulness to the drab room”

A cry or shout of approval.