[UNDER-1 4 a.] trans. To drain by means of underground trenches.
1805. R. W. Dickson, Pract. Agric., I. 13. Those clayey soils where water stagnates on the surface of the ground, and … cannot be removed by the more general modes of underdraining.
1832. Scoreby Farm Rep., 13, in Husb., III. (L.U.K.). The land was … completely underdrained with tiles.
1898. Yearbk. U. S. Dept. Agric., 318. If it is not underdrained in all wet spots, [surface draining] should be the first work done.
Hence Underdrainer.
1832. Scoreby Farm Rep., 25, in Husb., III. (L.U.K.). The great enemy to underdrainers, the mole.
