- (v.t.) To drain by forming an underdrain or underdrains in; as, to underdrain land.
- (n.) An underground drain or trench with openings through which the water may percolate from the soil or ground above.
Webster's Revised Unabridged Dictionary
| APA | Webster's. (2011). underdrain. Retrieved September 20, 2026, from http://smartdefine.org/underdrain/definitions/2076644 |
| Chicago | Webster's. 2011. "underdrain" http://smartdefine.org/underdrain/definitions/2076644 (accessed September 20, 2026). |
| Harvard | Webster's 2011, underdrain, Smart Define, viewed 20 September, 2026, <http://smartdefine.org/underdrain/definitions/2076644>. |
| MLA | Webster's. "underdrain" 28 May 2011. Web. 20 September 2026. <http://smartdefine.org/underdrain/definitions/2076644> |