Definitions: (1) that which cannot be shaken; (2) a bedrock reality
Quote: Truth is inconcussible—forever exempt from all transient vicissitudes, albeit never dead and formal, always vibrant and adaptable—radiantly alive. But when truth becomes linked with fact, then both time and space condition its meanings and correlate its values. Such realities of truth wedded to fact become concepts and are accordingly relegated to the domain of relative cosmic realities. — The Urantia Book (118:3.3)