verb (used with object), sub·ir·ri·gat·ed, sub·ir·ri·gat·ing.
to irrigate beneath the surface of the ground, as with water passing through a system of underground porous pipes or transmitted through the subsoil from ditches, etc.
Origin of subirrigate
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019
to irrigate (land) by means of an underground system of pipe lines or by natural moisture in the subsoil
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012