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: Webster's Revised Unabridged Dictionary (1913)