Most death-defying means extremely dangerous or terrifying. If we talk about the antonyms of this phrase, we can use safe, secure, protected, cautious or careful. Safe means free from harm or injury. Secure means protected from danger, harm, or loss. Protected means shielded from harm or damage. Cautious means acting with care, aware of potential risks. Careful means taking care to avoid potential danger. These antonyms clearly indicate that most death-defying is the opposite of safe, secure, protected, cautious or careful. So we can use these words as antonyms to communicate the opposite meaning of most death-defying.