Main entry: sincere, solemn, earnest
Definition: characterized by a firm and humorless belief in the validity of your opinions
Usage: both sides were deeply in earnest, even passionate; an entirely sincere and cruel tyrant; a film with a solemn social message
Main entry: sober, solemn, sedate, grave
Definition: dignified and somber in manner or character and committed to keeping promises
Usage: 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