Source : Webster's Revised Unabridged Dictionary (1913)

Elementary \El`e*men"ta*ry\, a. [L. elementarius: cf. F.
   ['e]l['e]mentaire.]
   1. Having only one principle or constituent part; consisting
      of a single element; simple; uncompounded; as, an
      elementary substance.

   2. Pertaining to, or treating of, the elements, rudiments, or
      first principles of anything; initial; rudimental;
      introductory; as, an elementary treatise.

   3. Pertaining to one of the four elements, air, water, earth,
      fire. ``Some luminous and fiery impressions in the
      elementary region.'' --J. Spencer.

Source : WordNet®

elementary
     adj 1: easy and not involved or complicated; "an elementary problem
            in statistics"; "elementary, my dear Watson"; "a
            simple game"; "found an uncomplicated solution to the
            problem" [syn: {simple}, {uncomplicated}, {unproblematic}]
     2: of or being the essential or basic part; "an elementary need
        for love and nurturing" [syn: {primary}]