underground

noun 0.637

geophyte

noun 0.582

souterrain

noun 0.580

subsurface

noun 0.579

hypo

noun 0.569

undercroft

noun 0.564

geode

noun 0.563

epigean

noun 0.559

basement

noun 0.552

aquifer

noun 0.541

hypothecium

noun 0.539

gleba

noun 0.533

cave

noun 0.533

subsoil

noun 0.531

deep geological repository

noun 0.529

underworld

noun 0.529

geotropism

noun 0.526

cellar

noun 0.526

ground ice

noun 0.523

hypocotyl

noun 0.523

subgrade

noun 0.522

grotto

noun 0.520

geosphere

noun 0.518

geodesic

noun 0.516

hypostome

noun 0.516

tomb

noun 0.515

sepulchre

noun 0.514

underbody

noun 0.514

undersurface

noun 0.514

underneath

noun 0.514

ground tissue

noun 0.512

geotherm

noun 0.511

hypandrium

noun 0.511

hydrogeology

noun 0.511

socle

noun 0.508

gemmule

noun 0.506

underfloor

noun 0.504

underside

noun 0.503

burial chamber

noun 0.503

soil

noun 0.503

troglodyte

noun 0.502

cavern

noun 0.502

entombment

noun 0.502

inhumation

noun 0.502

hypophysis

noun 0.501

hypodermis

noun 0.500