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"
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"
Someone or something that is solemn is very serious rather than cheerful or humorous. His solemn little face broke into smiles He looked solemn. = serious + solemnity so·lem·nity The setting for this morning's signing ceremony matched the solemnity of the occasion