- of, showing, or characterized by deep thought.
- of grave or somber disposition, character, or manner: a serious occasion; a serious man.
- being in earnest; sincere; not trifling: His interest was serious.
- requiring thought, concentration, or application: serious reading; a serious task.
- weighty or important: a serious book; Marriage is a serious matter.
- giving cause for apprehension; critical: The plan has one serious flaw.
- (of a patient's condition) having unstable or otherwise abnormal vital signs and other unfavorable indicators, as loss of appetite and poor mobility: patient is acutely ill.
- that which is of importance, grave, critical, or somber: You have to learn to separate the serious from the frivolous.
- grave in nature or disposition; thoughtful
- marked by deep feeling; in earnest; sincere
- concerned with important matters
- requiring effort or concentration
- giving rise to fear or anxiety; critical
- worthy of regard because of substantial quantity or quality
- extreme or remarkable
