Definition of "elementary"

elementary

/(ˌ)ɛlɪˈmɛnt(ə)ɹɪ/

adjective
comparative more elementary, superlative most elementary
1. Relating to the basic, essential or fundamental part of something.
2. Relating to an elementary school.
3. (physics) Relating to a subatomic particle.
  Quotations
  The physics of elementary particles in the 20th century was distinguished by the observation of particles whose existence had been predicted by theorists sometimes decades earlier.
  2012 March, Jeremy Bernstein, “A Palette of Particles”, in American Scientist‎, volume 100, number 2, page 146
4. (archaic) Sublunary; not celestial; belonging to the sublunary sphere, to which the four classical elements (earth, air, fire and water) were confined; composed of or pertaining to these four elements.
noun
plural elementaries
1. An elementary school.
2. (mythology, mysticism) A supernatural being associated with the elements.
  Quotations
  The demon (or elementary) of the South-West wind was particularly dreaded, as being the gini of fever and madness.
  1936, Rollo Ahmed, The Black Art, London: Long, page 45
  […] the spiritual man is either translated like Enoch and Elias to the higher state, or falls down lower than an elementary again […]
  2003, H P Blavatsky, The Letters of H. P. Blavatsky, volume 1
  But, in Africa these became definite in their Egyptian Types, by means of which we can follow their development from the elementaries of Chaos and Space into Celestial Intelligencers […]
  2007, Gerald Massey, The Natural Genesis, page 332