Being in a bad mood; displeased or sulky—often visible in one's face or behavior.
彼は朝から不機嫌で、ほとんど話さなかった。
He was in a bad mood all morning and barely spoke.
子どもが不機嫌になるとすぐに泣き出す。
When a child gets upset, they start crying right away.
上司が不機嫌だと職場の雰囲気が悪くなる。
When the boss is in a bad mood, the workplace atmosphere becomes unpleasant.