three r (adjective) primary/prime: basic, fundamental
Sinonime: basal,
beginning,
bottom,
central,
elemental,
elementary,
essential,
first, foundational, introductory, meat-and-potatoes,
original,
primitive,
principal,
radical,
rudimentary,
simple, three R's,
ultimate, underivative, underived,
underlyingAntonime: auxiliary,
secondary,
supplemental