Cheery means happy in a bright, friendly, almost sunny way — a cheery smile, a cheery hello, a cheery little kitchen with yellow cups. It is informal and light. Cheerful is a close word, but cheerful can be a steady, solid kind of happiness; cheery is the quick warmth, the bright greeting. You can use it of people, voices, colours, and rooms. Though actually, if someone is cheery when the news is bad, it can sound as if they are being bright on purpose, which some people find comforting and others find a little much.