of, pertaining to, or forming a base; fundamental

a basic principle; the basic ingredient.

Chemistry .

pertaining to, of the nature of, or containing a base.

not having all of the hydroxyls of the base replaced by the acid group, or having the metal or its equivalent united partly to the acid group and partly to oxygen.

alkaline.

Metallurgy . noting, pertaining to, or made by a steelmaking process (basic process) in which the furnace or converter is lined with a basic or nonsiliceous material, mainly burned magnesite and a small amount of ground basic slag, to remove impurities from the steel. Compare acid ( def. 8 ) .

Geology . (of a rock) having relatively little silica.

Military .

primary

basic training.

of lowest rank

airman basic.

Military .

basic training.

a soldier or airman receiving basic training.

Often, basics. something that is fundamental or basic; an essential ingredient, principle, procedure, etc.

to learn the basics of music; to get back to basics.

adjective

additional , extra , inessential , nonessential , outside , peripheral , secondary

adjective

basal , capital , central , chief , elemental , essential , indispensable , inherent , intrinsic , key , main , necessary , primary , primitive , principal , radical , substratal , underlying , vital , elementary , fundamental , ultimate , constitutional , constitutive , integral , beginning , rudimental , rudimentary , foundational , original , abecedarian , canonical , innate , irreducible , orthodox , primeval , sessile , substrate

noun

essential , fundamental , rudiment