<p><strong>Adjective</strong></p><ul><li>pertaining to rudiments or first principles; elementary.</li><li>Synonyms: initial, fundamental</li><li>Antonyms: advanced</li><li>Biology: of the nature of a rudiment; undeveloped or vestigial.</li><li>Synonyms: embryonic</li><li>Antonyms: mature</li><li>in an early, imperfect stage or form: How can we improve upon this admittedly rudimentary theory?</li></ul>