s]
| 1. | of, showing, or characterized by deep thought. |
| 2. | of grave or somber disposition, character, or manner: a serious occasion; a serious man. |
| 3. | being in earnest; sincere; not trifling: His interest was serious. |
| 4. | requiring thought, concentration, or application: serious reading; a serious task. |
| 5. | weighty or important: a serious book; Marriage is a serious matter. |
| 6. | giving cause for apprehension; critical: The plan has one serious flaw. |
| 7. | Medicine/Medical. (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. |
| 8. | that which is of importance, grave, critical, or somber: You have to learn to separate the serious from the frivolous. |
serious se·ri·ous (sēr'ē-əs)
adj.
Being of such import as to cause anxiety, as of a physical condition.