Synonyms to nethermost level

fundament, backside, base, basement, basis, beam, bearing wall, bed, bedding, bedrock, behind, belly, bottom, bottom side, breech, buttocks, derriere, downside, floor, flooring, fond, footing, foundation, fundamental, ground, grounds, groundwork, hardpan, lower side, lowest layer, lowest level, nether side, pavement, posterior, principle, radical, rear, riprap, rock bottom, rudiment, rump, seat, sill, solid ground, solid rock, stereobate, stylobate, substratum, substruction, substructure, terra firma, underbelly, underbuilding, undercarriage, undergirding, underlayer, underneath, underpinning, underside, understruction, understructure, Colonial bed, Hollywood bed, Japanese garden, a world-without-end bargain, accommodation, accommodations, alliance, alpine garden, aqueduct, arboretum, arroyo, band, basin, bassinet, bed and board, bed down, bed in, bed on, bed-davenport, bedstead, belt, berth, billet, board, board and room, bog garden, bond of matrimony, border, botanical garden, bottom on, break, br