from The Century Dictionary and Cyclopedia
- n. The application of water in such manner that it will reach the roots of agricultural crops without appearing at the surface. Under this term is also included natural subirrigation, or the occurrence of water beneath the surface (and of benefit to crops) due to natural causes. Subirrigation may be by percolation through sands or gravels, or through pipes or drain-tile suitably arranged. See the extract under subirrigate.
Sorry, no etymologies found.