<p><strong>Adjective:</strong></p><ul><li>causing fear, apprehension, or dread: a formidable opponent.</li><li><strong>Synonyms:</strong> horrible, frightful, fearful, menacing, threatening, appalling, dreadful</li><li><strong>Antonyms:</strong> pleasant</li><li>of discouraging or awesome strength, size, difficulty, etc.; intimidating: a formidable problem.</li><li>arousing feelings of awe or admiration because of grandeur, strength, etc.</li><li>of great strength; forceful; powerful: formidable opposition to the proposal.</li></ul>