Synonyms for BASIC: fundamental, elementary, elemental, essential, primitive, canonical, underlying, abecedarian; Antonyms for BASIC: nonessential, inessential, incidental, outside, peripheral, extra, additional, secondary.

The smartest way of sounding more eloquent when expressing yourself in English is to change basic, everyday words for their fancier versions. For instance, instead of saying “very big,” say “massive.” Instead of saying “detailed.” say “granular,” and instead of saying “not interesting,” say “banal.”