good humour (humor); good mood
pout; displeasure; ill humor; ill humour; sullenness
朝から上機嫌で出勤した。
I went to work in a good mood since morning.
上機嫌な様子で歌を口ずさんでいる。
He's humming a song looking cheerful.
プレゼントをもらって子供は上機嫌だ。
The child is in a great mood after getting a present.