borehole noun 2verb 1forms 3 noun2 •A hole bored into the ground to collect samples for analysis or to extract oil or water.The state of the groundwater is monitored at various boreholes in the area. •Any other hole that has been bored into something.There were little boreholes in the oak beam, indicating that insects had once taken some interest in it. verb1 •To bore a hole of this kind (in). formsboreholed · boreholing · boreholes
