What term means forever or eternity?

The term that denotes the concept of forever or eternity is perpetuity. This word refers to a state or condition that is everlasting and continues indefinitely without end. It is often used in various contexts, such as legal terms or financial agreements, emphasizing the permanence and continuity of certain obligations or rights.

While other terms have related meanings, they do not carry the same connotation. For instance, infinity generally refers to an unbounded quantity in mathematics and philosophy but does not specifically imply an unchangeable state. Timelessness often refers to the quality of being unaffected by the passage of time or lacking a temporal dimension, which is distinct from the idea of enduring perpetually. Endurance suggests the ability to withstand or last over time, but it does not inherently encompass the notion of eternity. Thus, perpetuity is the most fitting term for capturing an eternal or forever state.