What is Solemnly?

Solemnly definition and meaning on Dictionary terms:
grave, sober, or mirthless, as a person, the face, speech, tone, or mood: solemn remarks.
gravely or somberly impressive; causing serious thoughts or a grave mood: solemn music.
serious or earnest: solemn assurances.
characterized by dignified or serious formality, as proceedings; of a formal or ceremonious character: a solemn occasion.
made in due legal or other express form, as a declaration or agreement: a solemn oath.
marked or observed with religious rites; having a religious character: a solemn holy day.

uttered, prescribed, or made according to religious forms: a solemn ban on sacrifice.