List of underlying synonyms and underlying related words.
ab ovo, basal, basic, basilar, between the lines, bottom, cardinal, constituent, constitutive, covert, critical, crucial, cryptic, delitescent, dormant, elemental, elementary, esoteric, essential, foundational, fundamental, gut, hibernating, hidden, indispensable, latent, lurking, material, muffled, mystic, necessary, needful, obfuscated, obscured, occult, of the essence, original, possible, potential, primal, primary, primitive, radical, rudimentary, sleeping, submerged, substantial, substantive, under the surface, unmanifested, veiled, virtual, vital