Synonyms of foundational

1 Syllable

first

2 Syllables

bottom, simple, bottoms, basal, simplex, grass-roots, grassroots, central

3 Syllables

principal, lowermost, underlying, beginning, nethermost, undermost, essential, radicals, radical

4 Syllables

ultimate, elemental, underived, fundamental, rudimental, substrative, primitive, original

5 Syllables

elementary, introductory, meat-and-potatoes, axiological, rudimentary

6 Syllables

underivative