subfloor

Mane (Îngilîzî)

The floor structure supporting and underlying the visible flooring or other finishing surface such as a carpet

Hevwate

bedrock

subgrade

subsoil

substrate

substratum

subsurface

blind floor

counter floor

Werger

ψευδοπάτωμα

faux plancher

Untergrund

Etîmolojî (Îngilîzî)

From sub- + floor.