1 (in pl.) the elements or first principles of a subject.
2 (in pl.) an imperfect beginning of something undeveloped or yet to develop.
3 a part or organ imperfectly developed as being vestigial or having no function (e.g. the breast in males).
Etymology: F rudiment or L rudimentum (as RUDE, after elementum ELEMENT)
Useful english dictionary. 2012.