THESAURUS
Keel
argosy, ascend, bank, bark, base, baseboard, basement, be lost, boat, bottom, bucket, cant, capsize, careen, chassis, climb, craft, dado, decline, descend, dip, drop, fall, fall away, fall off, foot, footing, foundation, founder, frame, go down, go downhill, go uphill, grade, hooker, hulk, hull, incline, keel over, lean, leviathan, list, mopboard, nadir, overset, overturn, packet, pitch, pitchpole, rake, retreat, rise, scuttle, shelve, ship, shoemold, sidle, sink, slant, slope, sole, somersault, swag, sway, tilt, tip, toe, tub, turn over, turn turtle, uprise, upset, upset the boat, vessel, wainscot, watercraft
ROGET THESAURUS
Keel
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.