IPA: /ˈɡraʊndˌwɔːtər/
KK: /ˈgraʊndˌwɔːtər/
Water that is found underground, especially in soil or rock, and is a source for wells and springs.
Farmers often rely on groundwater for irrigation during dry seasons.
Groundwater → It is formed from "ground" (from Old English "grund", meaning the solid surface of the earth) and "water" (from Old English "wæter", meaning liquid that falls as rain or is found in rivers and lakes). The word "groundwater" refers to water that is found beneath the earth's surface in soil pore spaces and fractures of rock formations.
Think of the 'solid surface' ('ground') where 'water' is found beneath — that's what groundwater means.