<p><strong>Adjective</strong></p><ul><li>executed with the hand below the level of the shoulder and the palm turned upward and forward: an underhand delivery of a ball.</li><li>underhanded: an underhand deal with the chief of police.</li><li><strong>Synonyms:</strong> surreptitious, clandestine, sly, stealthy.</li></ul><p><strong>Adverb</strong></p><ul><li>with the hand below the level of the shoulder and the palm turned upward and forward: to bowl underhand.</li><li>secretly; stealthily; slyly.</li></ul>