An*nu"i*ty (&?;), n.; pl. Annuities (&?;). [LL. annuitas, fr. L. annus year: cf. F. annuité.] A sum of money, payable yearly, to continue for a given number of years, for life, or forever; an annual allowance.

• A financial instrument where a saver (annuitant) pays a lump sum in, then receives a smaller fixed amount of money back regularly over a certain fixed period (or sometimes a vague period such as "the remainder of the life of the annuitant"). This is the opposite of regular savings.