<p><strong>Noun</strong></p><ul><li>Usually rudiments.</li><li>the elements or first principles of a subject: the rudiments of grammar.</li><li>a mere beginning, first slight appearance, or undeveloped or imperfect form of something: the rudiments of a plan.</li><li>Biology. an organ or part incompletely developed in size or structure, as one in an embryonic stage, one arrested in growth, or one with no functional activity, as a vestige.</li></ul>