All 14 Uses of

solemn
in
The Iliad by Homer - (translated by: Butler)

Therefore I say, and swear it with a great oath—nay, by this my sceptre which shalt sprout neither leaf nor shoot, nor bud anew from the day on which it left its parent stem upon the mountains—for the axe stripped it of leaf and bark, and now the sons of the Achaeans bear it as judges and guardians of the decrees of heaven—so surely and solemnly do I swear that hereafter they shall look fondly for Achilles and shall not find him.†
Book 1

solemnly = with seriousness and dignity

This is the most solemn promise that I can give to any god.†
Book 1 *

solemn = very serious--possibly dignified

Cruel Jove gave me his solemn promise that I should sack the city of Priam before returning, but he has played me false, and is now bidding me go ingloriously back to Argos with the loss of much people.†
Book 2

Think that the Achaeans and Trojans have sworn to a solemn covenant, and that they have each been numbered—the Trojans by the roll of their householders, and we by companies of ten; think further that each of our companies desired to have a Trojan householder to pour out their wine; we are so greatly more in number that full many a company would have to go without its cup-bearer.†
Book 2

Let him who shall be victorious and prove to be the better man take the woman and all she has, to bear them to his home, but let the rest swear to a solemn covenant of peace whereby you Trojans shall stay here in Troy, while the others go home to Argos and the land of the Achaeans.†
Book 3

Let him who shall be victorious and prove to be the better man take the woman and all she has, to bear them to his own home, but let the rest swear to a solemn covenant of peace.†
Book 3

He went up to Priam and said, "Son of Laomedon, the princes of the Trojans and Achaeans bid you come down on to the plain and swear to a solemn covenant.†
Book 3

We are to swear to a solemn covenant of peace whereby we others shall dwell here in Troy, while the Achaeans return to Argos and the land of the Achaeans.†
Book 3

Let us give up Argive Helen and her wealth to the sons of Atreus, for we are now fighting in violation of our solemn covenants, and shall not prosper till we have done as I say.†
Book 7

Cruel Jove gave me his solemn promise that I should sack the city of Troy before returning, but he has played me false, and is now bidding me go ingloriously back to Argos with the loss of much people.†
Book 9

Juno trembled as he spoke, and said, "May heaven above and earth below be my witnesses, with the waters of the river Styx—and this is the most solemn oath that a blessed god can take—nay, I swear also by your own almighty head and by our bridal bed—things over which I could never possibly perjure myself—that Neptune is not punishing Hector and the Trojans and helping the Achaeans through any doing of mine; it is all of his own mere motion because he was sorry to see the Achaeans hard pressed at their ships: if I were advising him, I should tell him to do as you bid him."†
Book 15

Each was trying to make his own case good, and the people took sides, each man backing the side that he had taken; but the heralds kept them back, and the elders sate on their seats of stone in a solemn circle, holding the staves which the heralds had put into their hands.†
Book 18

I might make the Trojans, by the mouths of their princes, take a solemn oath that they would hide nothing, but would divide into two shares all that is within the city—but why argue with myself in this way?†
Book 22

As soon as they reached Agamemnon's tent they told the serving-men to set a large tripod over the fire in case they might persuade the son of Peleus to wash the clotted gore from this body, but he denied them sternly, and swore it with a solemn oath, saying, "Nay, by King Jove, first and mightiest of all gods, it is not meet that water should touch my body, till I have laid Patroclus on the flames, have built him a barrow, and shaved my head—for so long as I live no such second sorrow shall ever draw nigh me.†
Book 23

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.