形容词

1. 欢快的;高兴的;兴高采烈的
Someone who is cheerful is happy and shows this in their behaviour.

1. being full of or promoting cheer
having or showing good spirits

e.g. her cheerful nature
a cheerful greeting
a cheerful room
as cheerful as anyone confined to a hospital bed could be

2. pleasantly (even unrealistically) optimistic

Synonym: pollyannaishupbeat