Noun
An annuity, with the benefit of survivorship, or a loan raised on life annuities with the benefit of survivorship. Thus, an annuity is shared among a number, on the principle that the share of each, at his death, is enjoyed by the survivors, until at last the whole goes to the last survivor, or to the last two or three, according to the terms on which the money is advanced. Used also adjectively; as, tontine insurance.
Source: Webster's dictionary