AF, ab ovo, abecedarian, aboriginal, antenatal, audio frequency, austere, autochthonous, axiom, bare, basal, base, basement, basic, basilar, basis, bearing wall, bed, bedding, bedrock, beginning, bench mark, bottom, budding, cardinal, cardinal point, center, central, chaste, chief thing, climax, component, constituent, constitutional, constitutive, core, cornerstone, creative, crisis, critical, critical point, crucial, crux, dominant, element, elemental, elementary, elements, elixir, embryonic, essence, essential, essential matter, factor, fetal, first, floor, flooring, flower, focal, focus, fond, footing, formative, foundation, foundational, frequency, fundament, fundamental tone, generative, genetic, germinal, gestatory, gist, grammar, gravamen, great point, ground, grounds, groundwork, gut, hardpan, harmonic, heart, high point, homely, homespun, homogeneous, hypostasis, important, important thing, in embryo, in its infancy, in ovo, in the bud, inaugural, inceptive, inchoate, inchoative, incipient, incunabular, indispensable, indivisible, infant, infantile, inherent, initial, initiative, initiatory, inner essence, intonation, intrinsic, introductory, inventive, irreducible, issue, kernel, keystone, landmark, law, life-and-death, life-or-death, main, main point, main thing, marrow, material, material point, meat, mere, milestone, monolithic, monotone, monotony, nascent, natal, necessary, needful, nub, nucleus, nuts and bolts, of a piece, of the essence, of vital importance, organic, original, overtone, paramount, part and parcel, partial, partial tone, parturient, pavement, pitch, pith, pivot, plain, postnatal, postulate, pregnant, prenatal, primal, primary, prime, primeval, primitive, primogenial, primordial, principal, principium, principle, principles, pristine, procreative, protogenic, pure, pure and simple, quid, quiddity, quintessence, quintessential, radical, real issue, requisite, riprap, rock bottom, rudiment, rudimental, rudimentary, rudiments, rule, salient point, sap, seat, seminal, severe, sill, simon-pure, simple, sine qua non, single, solid ground, solid rock, soul, spare, spirit, stark, stereobate, stuff, stylobate, substance, substantial, substantive, substantive point, substratum, substruction, substructure, terra firma, the bottom line, the nitty-gritty, the point, theorem, tone, tonelessness, turning point, unadorned, uncluttered, underbuilding, undercarriage, undergirding, underlying, underpinning, understruction, understructure, undifferenced, undifferentiated, uniform, ur, vital