<p><strong>Adjective</strong></p><ul><li>causing or tending to cause death; fatal; lethal: a deadly poison.</li><li>aiming to kill or destroy; implacable: a deadly enemy.</li><li>like death: a deadly pallor.</li><li>excruciatingly boring: The dinner party was absolutely deadly.</li><li>Synonyms: dreary, tedious, dull</li><li>excessive; inordinate: deadly haste.</li><li>extremely accurate: Annie Oakley was a deadly shot.</li></ul><p><strong>Adverb</strong></p><ul><li>in a manner resembling or suggesting death: deadly pale.</li><li>excessively; completely: deadly dull.</li></ul>