
Sullen
Mood Indicator
 Use 'sullen' to describe someone showing irritation or ill humor by a gloomy silence. 
After losing the game, he had a sullen demeanor.
 Not Rude
 'Sullen' suggests a silent moodiness, not rudeness or meanness. 
Her sullen attitude was more about her sadness than any dislike for us.
 Temporary State
 'Sullen' often implies a temporary state rather than a permanent trait. 
He's usually cheerful, just a bit sullen today.