'Solemn' in the Bible

It is to be a sabbath of solemn rest for you, that you may humble your souls; it is a permanent statute.

‘On the eighth day you shall have a solemn assembly; you shall do no laborious work.

Six days you shall eat unleavened bread, and on the seventh day there shall be a solemn assembly to the Lord your God; you shall do no work on it.

And Jehu said, “Sanctify a solemn assembly for Baal.” And they proclaimed it.

On the eighth day they held a solemn assembly, for the dedication of the altar they observed seven days and the feast seven days.

He read from the book of the law of God daily, from the first day to the last day. And they celebrated the feast seven days, and on the eighth day there was a solemn assembly according to the ordinance.

“Bring your worthless offerings no longer,Incense is an abomination to Me.New moon and sabbath, the calling of assemblies—I cannot endure iniquity and the solemn assembly.

And it will be to them like a false divination in their eyes; they have sworn solemn oaths. But he brings iniquity to remembrance, that they may be seized.

Consecrate a fast,Proclaim a solemn assembly;Gather the eldersAnd all the inhabitants of the landTo the house of the Lord your God,And cry out to the Lord.

Blow a trumpet in Zion,Consecrate a fast, proclaim a solemn assembly,

“I hate, I reject your festivals,Nor do I delight in your solemn assemblies.