<p><strong>adjective</strong></p><ul><li>Light in weight.</li><li>Being lighter in weight, texture, etc., than another item or object of identical use, quality, or function: a lightweight alloy for ship construction.</li><li>Without seriousness of purpose; trivial or trifling: lightweight reading.</li><li>Of or relating to a lightweight: He's the new lightweight contender.</li><li>(Of a horse, especially a hunter) able to carry up to 165 pounds (75 kilograms).</li></ul><p><strong>noun</strong></p><ul><li>A person of less than average weight.</li><li>Informal: a person who is of little influence, importance, or effect.</li><li>A boxer or other contestant intermediate in weight between a featherweight and a welterweight, especially a professional boxer weighing between 126 and 135 pounds (56.7–61 kilograms).</li></ul>