The word "undestroyable" is a strong adjective that means something or someone cannot be destroyed. There are several synonyms for this word, including indestructible, impervious, invincible, unbreakable, bulletproof, impenetrable, and resilient. These words are commonly used to describe objects or materials that are incredibly strong, durable, and resistant to damage. They can also be used to describe people who are strong-willed, persistent, and able to overcome any obstacle. While the word undestroyable is not commonly used in everyday language, its synonyms are frequently used in various contexts including engineering, construction, and even personal attributes.