All 11 Uses of

solemn
in
The Mill on the Floss

So they went in procession along the bright and slippery corridor, dimly lighted by the semi-lunar top of the window which rose above the closed shutter; it was really quite solemn.†
Chpt 1.9

solemn = very serious--possibly dignified

Aunt Pullet paused and unlocked a door which opened on something still more solemn than the passage,—a darkened room, in which the outer light, entering feebly, showed what looked like the corpses of furniture in white shrouds.†
Chpt 1.9

She maintained a silence characterized by head-shaking, until they had all issued from the solemn chamber and were in her own room again.†
Chpt 1.9 *

He took no notice of Tom's return, being too entirely absorbed in the cut and thrust,—the solemn one, two, three, four; and Tom, not without a slight feeling of alarm at Mr. Poulter's fixed eye and hungry-looking sword, which seemed impatient for something else to cut besides the air, admired the performance from as great a distance as possible.†
Chpt 2.4

The chest had belonged to his father and his father's father, and it had always been rather a solemn business to visit it.†
Chpt 3.4

A strange thrill of awe passed through Maggie while she read, as if she had been wakened in the night by a strain of solemn music, telling of beings whose souls had been astir while hers was in stupor.†
Chpt 4.3

At last he looked up and said coldly,— "Now, then, Maggie, there are but two courses for you to take,—either you vow solemnly to me, with your hand on my father's Bible, that you will never have another meeting or speak another word in private with Philip Wakem, or you refuse, and I tell my father everything; and this month, when by my exertions he might be made happy once more, you will cause him the blow of knowing that you are a disobedient, deceitful daughter, who throws away her own respectability by clandestine meetings with the son of a man that has helped to ruin her father.†
Chpt 5.5

solemnly = with seriousness and dignity

Tom threatens to tell my father, and he couldn't bear it; I have promised, I have vowed solemnly, that we will not have any intercourse without my brother's knowledge.†
Chpt 5.5

"But, dear," said Maggie, falteringly, "I promised Tom very solemnly, before my father's death,—I promised him I would not speak to Philip without his knowledge and consent.†
Chpt 6.3

Her feeling under his words was complicated by the allusion to the last scene between her father and Wakem; and at length that painful, solemn memory surmounted the immediate grievance.†
Chpt 6.4

solemn = very serious--possibly dignified

She was silent for a few moments, with her eyes fixed on the ground; then she drew a deep breath, and said, looking up at him with solemn sadness,— "Oh, it is difficult,—life is very difficult!†
Chpt 6.11

Definitions:

(1) (solemn)
in a very serious (and often dignified) manner
(2) (meaning too rare to warrant focus)
meaning too rare to warrant focus:

Less commonly, solemn can mean that something was done with great or appropriate ceremony. It can also be used to describe something as dark or undecorated.