s, -bohr-]
| 1. | requiring much work, exertion, or perseverance: a laborious undertaking. |
| 2. | characterized by or requiring extreme care and much attention to detail: laborious research. |
| 3. | characterized by or exhibiting excessive effort, dullness, and lack of spontaneity; labored: a strained, laborious plot. |
| 4. | given to or diligent in work: a careful, laborious craftsman. |