Sure ground refers to a safe and secure footing that provides stability and confidence. The word 'assured' is a synonym for sure ground. It denotes a sense of confidence and trust that one has in their stance. Another synonym for sure ground is 'firmament', which signifies an unshakeable foundation that is capable of withstanding any challenge. 'Solid ground' is another synonym that connotes a stable and reliable platform that does not give way or waver. Other words that can be used as synonyms for sure ground include 'steadfast', 'stable', 'assured', and 'unwavering'. All of these synonyms imply a sense of confidence and assurance in one's footing, making it clear that they are standing on secure and stable ground.