n. Anything which is in an undeveloped state; the principle which lies at the beginning or bottom of any development; an unformed or unfinished beginning.n. An element or first principle of any art or science; especially, in the plural, the beginning, first steps, or introduction to any branch of knowledge; the elements or elementary notions.n. In biology: That which is rudimentary; that which is in its first or an early stage of development, which may or may not be continued; the beginning or foundation of any part or organ: as, the rudiment of the embryo which is to go on to maturity; the rudiment of an organ whose further development has been arrested or abortedn. That which is vestigial; a vestigial or aborted part, organ, or structure; an abortion; a vestige.To furnish with first principles or rules; ground; settle in first principles.