solemn

(s) dignified and somber in manner or character and committed to keeping promises
- a grave God-fearing man
- a quiet sedate nature
- as sober as a judge
- a solemn promise
- the judge was solemn as he pronounced sentence
grave, sedate, sober,
(s) characterized by a firm and humorless belief in the validity of your opinions
- both sides were deeply in earnest, even passionate
- an entirely sincere and cruel tyrant
- a film with a solemn social message
earnest, sincere,

grave sedate sober earnest sincere

Solea soled

solely Solent soleus

solemness solemnisation solemnise solemnity Solemnity of Mary solemnization solemnize solemnly