Unbreakable/ʌnˈbreɪkəbl/ Definition 1 of 2Pro Tip 1/3Physical Durability Often used for materials that withstand force without breaking or wearing out. The unbreakable windows survived the storm. Pro Tip 2/3Not Literal Sometimes used metaphorically to describe concepts or systems that are robust. Their unbreakable code of honor defines their actions. Pro Tip 3/3Not Invincible Despite 'unbreakable', things can still suffer damage or wear over time, just not easily. The toy is unbreakable, but it's not immune to scratches.