Underlying
Part of speech: adjective
Definition: lying underneath basic or fundamental implicit
Example sentence: Looking ahead, I believe that the underlying importance of higher education, of science, of technology, of research and scholarship to our quality of life, to the strength of our economy, to our security in many dimensions will continue to be the most important message.
Rudimentary
Part of speech: adjective
Definition: of or related to one or more rudimentsBasic; minimal; with less than, or only the minimum, necessary.