pertaining to or dealing with elements, rudiments, or first principles

an elementary grammar.

of or pertaining to an elementary school

elementary teachers.

of the nature of an ultimate constituent; simple or uncompounded.

pertaining to the four elements, earth, water, air, and fire, or to the great forces of nature; elemental.

Chemistry . of or noting one or more elements.

adjective

abstruse , advanced , complex , complicated , compound , difficult , hard , intricate , involved , secondary

adjective

abcs , abecedarian , basal , beginning , child’s play , clear , duck soup * , easy , elemental , essential , facile , foundational , fundamental , initial , introductory , meat and potatoes * , original , plain , prefatory , preliminary , primary , primitive , primo , rudimentary , simplest , simplex , simplified , straightforward , substratal , uncomplex , uncomplicated , underlying , basic , ultimate , rudimental , constituent , crude , simple , uncompounded