<p><strong>Adjective</strong></p><ul><li>Pertaining to muscles, parts, or intervals between the ribs.</li><li>Situated between the ribs.</li><li>Shipbuilding: noting a structural member situated between or divided by continuous members, as frames or keelsons.</li></ul><p><strong>Noun</strong></p><ul><li>An intercostal muscle, member, or space.</li></ul>