* Formal: "The endowment fund will provide a perpetuity of income for the university library."
* Financial: "The bond's perpetuity means that it will pay interest forever."
* Figurative: "Her love for her family was a perpetuity, never fading with time."
* Philosophical: "The search for meaning is a perpetuity in the human condition."
Key point: "Perpetuity" often refers to something that continues forever, but it can also be used figuratively for things that seem endless or unchanging.