THESAURUS
nadir
base, baseboard, basement, bedrock, bottom, chassis, dado, foot, footing, foundation, frame, keel, lower strata, lowest level, lowest point, mopboard, shoemold, sole, toe, underlying level, wainscot
ROGET THESAURUS
nadir
Base
N
base, basement, plinth, dado, wainscot, baseboard, mopboard, bedrock, hardpan, foundation, substructure, substratum, ground, earth, pavement, floor, paving, flag, carped, ground floor, deck, footing, ground work, basis, hold, bilge, bottom,
nadir, foot, sole, toe, hoof, keel, root, centerboard, bottom, undermost, nethermost, fundamental, founded on, based on, grounded on, built on.