An annuity is a promised stream of money paid on a set timetable — classically once a year, and often until the person dies. Banks and insurance companies sell it as a product: you give them a lump of money (or pay in over time), and they pay you a fixed amount for life, or for a fixed number of years. In real talk, people also call monthly or quarterly payouts an annuity; the old “once a year” idea sits in the word, but the product is about money you can count on, again and again, not about the calendar. It is a formal money-and-law word — pensions, insurance, retirement — not a chat word. A work pension feels close (regular money after you stop working), but an annuity is the contract itself: a promise to keep paying, often bought, not earned as wages. Some modern products let the amount rise and fall with markets; the core learner sense is still the fixed, regular one.