cheer

a cry or shout of approval

the quality of being cheerful and dispelling gloom; "flowers added a note of cheerfulness to the drab room"

give encouragement to

show approval or good wishes by shouting; "everybody cheered the birthday boy"

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

spur on or encourage especially by cheers and shouts; "The crowd cheered the demonstrating strikers"