Difference between Glum and Sullen

GLUM vs SULLEN: NOUN

The quality or state of being moody, melancholy, and gloomy or an instance of it.
The blues. Often used with the:
A sullen look; a frown.
Sullenness.

Being but one; unique; hence, rare; remarkable.
Remaining alone through ill humor; unsociable; silent and cross; sulky; morose; glum.
Gloomy; dismal; somber.
Sad; sorrowful; melancholy.
Slow-moving; sluggish; dull: as, a sullen pace.
Malignant; unpropitious; foreboding ill; baleful.
Synonyms Gloomy, Sullen, Sulky, Morose, Splenetic. These words are arranged in the order of their intensity and of their degrees of activity toward others. Gloomy has the figurative suggestion of physical gloom or darkness: the gloomy man has little brightness in his mind, or he sees little light ahead. The sullen man is silent because he is sluggishly angry and somewhat bitter, and he repels friendly advances by silence and a lowering aspect rather than by words. The sulky person persists in being sullen beyond all reason and for mere whim: the young are often sulky. In the morose man there is an element of hate, and he meets advances with rudeness or cruel words: the young have rarely development of character enough to be morose. The splenetic man is sulky and peevish, with frequent outbursts of irritation venting itself upon persons or things. Any of these words may indicate either a temporary mood or a strong tendency of nature.
To make sullen, morose, or sulky.
Being alone; solitary; lonely; hence, single; unmarried.

Downbeat, Grim, Bleak, Long faced, Ill natured, Saturnine, Dark, Glowering, Moody, Sour, Sullen, Dejected, Morose, Dour, Gloomy

Forlorn, Surly, Lowering, Ill natured, Heavy, Threatening, Cloudy, Sour, Dark, Saturnine, Dour, Glum, Glowering, Moody, Morose

Downbeat, Grim, Bleak, Long faced, Ill natured, Saturnine, Dark, Glowering, Moody, Sour, Sullen, Dejected, Morose, Dour, Gloomy

Forlorn, Surly, Lowering, Ill natured, Heavy, Threatening, Cloudy, Sour, Dark, Saturnine, Dour, Glum, Glowering, Moody, Morose

Scratch a glum Greek, and you'll find a bull.
You look as glum as a Jesuit in Lent.
I avoided parachuting actors portraying Bond and the Queen: no wonder she looked so glum.
They look glum but these Daily Express women were in fact putting on an act.
Or do I drag it by my side half-heartedly, glum and sullen?.
His normally glum expression was replaced by the most charming smile.
Like him she wore hard shoes with a glum expression.
Perhaps this makes you feel glum about your current ass.
Turn and tell your partner why Fred is glum.
Animals, majestic landscapes, glum contestants on a boat.

Feeling irritably sullen and churlish in mood or manner.
Instead he clamped his jaws shut, sullen and morose.
You insisted to a room full of sullen stares.
Sullen, sulky, hedge or fence made of brushwood.
The slug struck rock with a sullen thwack.
Now we are sullen in this sable mire.
Official Winged Victory For The Sullen Merch Store.
Moya, son ef circus manager Stafford Sullen Mr.
How is a grumpy, sullen staff member supposed to placate a grumpy, sullen guest?
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