Synonyms to indispensable

fundamental, 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, indivisible, infant, infantile, inherent, initial, initiative, initiatory, in