elementary -
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"
elementary -
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.
Wikipedia
ELEMENTARY of elementary recursive functions is the union of the classes in the exponential hierarchy. The name was coined by Laszlo Kalmar, in the context of recursive functions and undecidability; most problems in it are far from elementary. Some natural recursive problems lie outside ELEMENTARY, and are thus NONELEMENTARY.
OmegaWiki Dictionary
Ω
elementary Relating to the basic, essential or fundamental part of something.