Source : Webster's Revised Unabridged Dictionary (1913)

Annuity \An*nu"i*ty\, n.; pl. {Annuities}. [LL. annuitas, fr. L.
   annus year: cf. F. annuit['e].]
   A sum of money, payable yearly, to continue for a given
   number of years, for life, or forever; an annual allowance.