1.  foundation(n = noun.linkdef) Array - the basis on which something is grounded; "there is little foundation for his objections"
is a kind of relation
has particulars: basis, footing, ground, grass roots
Derived form verb found₃

2.  foundation(n = noun.group) Array - an institution supported by an endowment; Array
is a kind of financial institution, financial organisation, financial organization
has particulars: charity
Derived form verb found₁

3.  foundation(n = noun.artifact) base, foot, fundament, groundwork, substructure, understructure - lowest support of a structure; "it was built on a base of solid rock"; "he stood at the foot of the tower"
is a kind of support
is a part of construction, structure
has particulars: bed, raft foundation

4.  foundation(n = noun.cognition) grounding - education or instruction in the fundamentals of a field of knowledge; "he lacks the foundation necessary for advanced study"; "a good grounding in mathematics"
is a kind of education

5.  foundation(n = noun.cognition) base, basis, cornerstone, fundament, groundwork - the fundamental assumptions from which something is begun or developed or calculated or explained; "the whole argument rested on a basis of conjecture"
is a kind of assumption, supposal, supposition
is a part of explanation
has particulars: meat and potatoes
Derived form verb found₃

6.  foundation(n = noun.artifact) foundation garment - a woman's undergarment worn to give shape to the contours of the body; Array
is a kind of undergarment, unmentionable
has particulars: corset, girdle, stays, roll-on

7.  foundation(n = noun.act) creation, founding, initiation, innovation, instauration, institution, introduction, origination - the act of starting something for the first time; introducing something new; "she looked forward to her initiation as an adult"; "the foundation of a new scientific society"
is a kind of beginning, commencement, start
has particulars: authorship, paternity
Derived form verb found₂

1.  The act of founding, fixing, establishing, or beginning to erect. [1913 Webster]

2.  That upon which anything is founded; that on which anything stands, and by which it is supported; the lowest and supporting layer of a superstructure; groundwork; basis. [1913 Webster]
"Behold, I lay in Zion, for a foundation, a stone . . . a precious corner stone, a sure foundation." [1913 Webster]
"The foundation of a free common wealth." [1913 Webster]

3.  The lowest and supporting part or member of a wall, including the base course (see Base course (a), under Base, n.) and footing courses; in a frame house, the whole substructure of masonry. [1913 Webster]

4.  A donation or legacy appropriated to support a charitable institution, and constituting a permanent fund; endowment. [1913 Webster]
"He was entered on the foundation of Westminster." [1913 Webster]

5.  That which is founded, or established by endowment; an endowed institution or charity; as, the Ford Foundation. [1913 Webster]
"Against the canon laws of our foundation." [1913 Webster]

foundation, n.
1 a the solid ground or base, natural or artificial, on which a building rests. b (usu. in pl.) the lowest load-bearing part of a building, usu. below ground level.
2 a body or ground on which other parts are overlaid.
3 a basis or underlying principle; groundwork (the report has no foundation).
4 a the act or an instance of establishing or constituting (esp. an endowed institution) on a permanent basis. b such an institution, e.g. a monastery, college, or hospital.
5 (in full foundation garment) a woman's supporting undergarment, e.g. a corset.

Idiom:
foundation cream a cream used as a base for applying cosmetics. foundation-stone
1 a stone laid with ceremony to celebrate the founding of a building.
2 the main ground or basis of something.

Derivative:
foundational adj.

Etymology:
ME f. OF fondation f. L fundatio -onis (as FOUND(2))

N  preparation, providing, provision, providence, anticipation, precaution, preconcertation, predisposition, forecast, rehearsal, note of preparation, arrangement, clearance, adjustment, tuning, equipment, outfit, accouterment, armament, array, ripening, maturation, evolution, elaboration, concoction, digestion, gestation, batching, incubation, sitting, groundwork, first stone, cradle, stepping-stone, foundation, scaffold, scaffolding, echafaudage, training, inurement, novitiate, cooking, cookery, brewing, culinary art, tilling, plowing sowing, semination, cultivation, preparedness, readiness, ripeness, mellowness, maturity, un impromptu fait a loisir, preparer, trainer, pioneer, trailblazer, avant-courrier, avant-coureur, voortrekker, sappers and miners, pavior, navvy, packer, stevedore, warming pan, preparing, in preparation, in course of preparation, in agitation, in embryo, in hand, in train, afoot, afloat, on foot, on the stocks, on the anvil, under consideration, brewing, batching, forthcoming, brooding, in store for, in reserve, precautionary, provident, preparative, preparatory, provisional, inchoate, under revision, preliminary, prepared, in readiness, ready, ready to one's band, ready made, ready cut and dried: made to one's hand, handy, on the table, in gear, in working order, in working gear, snug, in practice, ripe, mature, mellow, pukka, practiced, labored, elaborate, highly-wrought, smelling of the lamp, worked up, in full feather, in best bib and tucker, in harness, at harness, in the saddle, in arms, in battle array, in war paint, up in arms, armed at all points, armed to the teeth, armed cap a pie, sword in hand, booted and spurred, in utrumque paratus, semper paratus, on the alert, at one's post, in preparation, in anticipation of, against, for, abroach, a bove majori discit arare minor, looking before and after, si vis pacem para bellum.

N  stability, immutability, unchangeability unchangeableness, constancy, stable equilibrium, immobility, soundness, vitality, stabiliment, stiffness, ankylosis, solidity, aplomb, establishment, fixture, rock, pillar, tower, foundation, leopard's spots, Ethiopia's skin, permanence, obstinacy, unchangeable, immutable, unaltered, unalterable, not to be changed, constant, permanent, invariable, undeviating, stable, durable, perennial, fixed, steadfast, firm, fast, steady, balanced, confirmed, valid, fiducial, immovable, irremovable, riveted, rooted, settled, established, vested, incontrovertible, stereotyped, indeclinable, tethered, anchored, moored, at anchor, on a rock, rock solid, firm as a rock, firmly seated, firmly established, deep-rooted, ineradicable, inveterate, obstinate, transfixed, stuck fast, aground, high and dry, stranded, stuck, jammed, unremovable, quiescent, deterioration, indefeasible, irretrievable, intransmutable, incommutable, irresoluble, irrevocable, irreversible, reverseless, inextinguishable, irreducible, indissoluble, indissolvable, indestructible, undying, imperishable, incorruptible, indelible, indeciduous, insusceptible, insusceptible of change, Int, stet, littera scripta manet.

N  cause, origin, source, principle, element, occasioner, prime mover, primum mobile, vera causa, author, mainspring, agent, leaven, groundwork, foundation, spring, fountain, well, font, fountainhead, spring head, wellhead, fons et origo, genesis, descent, remote cause, influence, pivot, hinge, turning point, lever, crux, fulcrum, key, proximate cause, causa causans, straw that breaks the camel's back, ground, reason, reason why, why and wherefore, rationale, occasion, derivation, final cause, les dessous des cartes, undercurrents, rudiment, egg, germ, embryo, bud, root, radix radical, etymon, nucleus, seed, stem, stock, stirps, trunk, tap-root, gemmule, radicle, semen, sperm, nest, cradle, nursery, womb, nidus, birthplace, hotbed, causality, causation, origination, production, caused, causal, original, primary, primitive, primordial, aboriginal, protogenal, radical, embryonic, embryotic, in embryo, in ovo, seminal, germinal, at the bottom of, connate, having a common origin, because, behind the scenes, causa latet vis est notissima, felix qui potuit rerum cognoscere causas.

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.

N  support, ground, foundation, base, basis, terra firma, bearing, fulcrum, bait, caudex crib, point d'appui, pou sto, purchase footing, hold, locus standi, landing place, landing stage, stage, platform, block, rest, resting place, groundwork, substratum, riprap, sustentation, subvention, floor, supporter, aid, prop, stand, anvil, fulciment, cue rest, jigger, monkey, stay, shore, skid, rib, truss, bandage, sleeper, stirrup, stilts, shoe, sole, heel, splint, lap, bar, rod, boom, sprit, outrigger, ratlings, staff, stick, crutch, alpenstock, baton, staddle, bourdon, cowlstaff, lathi, mahlstick, post, pillar, shaft, thill, column, pilaster, pediment, pedicle, pedestal, plinth, shank, leg, socle, zocle, buttress, jamb, mullion, abutment, baluster, banister, stanchion, balustrade, headstone, upright, door post, jamb, door jamb, frame, framework, scaffold, skeleton, beam, rafter, girder, lintel, joist, travis, trave, corner stone, summer, transom, rung, round, step, sill, angle rafter, hip rafter, cantilever, modillion, crown post, king post, vertebra, columella, backbone, keystone, axle, axletree, axis, arch, mainstay, trunnion, pivot, rowlock, peg, tiebeam, thole pin, board, ledge, shelf, hob, bracket, trevet, trivet, arbor, rack, mantel, mantle piece, mantleshelf, slab, console, counter, dresser, flange, corbel, table, trestle, shoulder, perch, horse, easel, desk, clotheshorse, hatrack, retable, teapoy, seat, throne, dais, divan, musnud, chair, bench, form, stool, sofa, settee, stall, arm chair, easy chair, elbow chair, rocking chair, couch, fauteuil, woolsack, ottoman, settle, squab, bench, aparejo, faldstool, horn, long chair, long sleeve chair, morris chair, lamba chauki, lamba kursi, saddle, pannel, pillion, side saddle, pack saddle, pommel, bed, berth, pallet, tester, crib, cot, hammock, shakedown, trucklebed, cradle, litter, stretcher, bedstead, four poster, French bed, bunk, kip, palang, bedding, bichhona, mattress, paillasse, pillow, bolster, mat, rug, cushion, footstool, hassock, tabouret, tripod, monopod, Atlas, Persides, Atlantes, Caryatides, Hercules, supporting, supported, fundamental, dorsigerous, astride on, straddle.

foundation garment, foundation stone, lay the foundation, national science foundation, philanthropic foundation, private foundation, raft foundation, without foundation