Synonyms of underlying

1 Syllable

nub, root

2 Syllables

prime, hidden, veiled, latent, bottom, bottoms, basal, simplex, grass-roots, grassroots, basic, lurking, vital, crucial, needful

3 Syllables

concealed, critical, subjacent, capitals, capital, lowermost, substratal, nethermost, vestigial, undermost, essential, cardinal, radicals, primary, intrinsic, bottom-line, radical

4 Syllables

elemental, nitty-gritty, foundational, unevolved, unrealized, fundamental, rudimental, substrative, overarching, primitive, necessary

5 Syllables

elementary, meat-and-potatoes, axiological, indispensable