rudiment

n. 1 (in pl.) Elements or first principles of a subject. 2 (in pl.) Imperfect beginning of something undeveloped or yet to develop. 3 vestigial or undeveloped part or organ.  rudimentary adj. [latin: related to *rude]

n. That which is unformed or undeveloped; the principle which lies at the bottom of any development; an unfinished beginning.