Synonym word of un complex:

ABCs, abecedarian, basal, beginning, child's play, clear, duck soup, easy, elemental, essential, facile, foundational, fundamental, initial, introductory, meat and potatoes, original, plain, prefatory, preliminary, primary, primitive, primo, rudimentary, simplest, simplex, simplified, straightforward, substratal, uncomplex, uncomplicated, underlying