equal decrement of life

Webster's Dictionary (GCIDE)

1.The state of becoming gradually less; decrease; diminution; waste; loss. [1913 Webster]

Twit me with the decrements of my pendants.— Ford.[1913 Webster]

Rocks, mountains, and the other elevations of the earth suffer a continual decrement.— Woodward.[1913 Webster]

2.The quantity lost by gradual diminution or waste; -- opposed to increment. [1913 Webster]

3.(Crystallog.) A name given by Ha["u]y to the successive diminution of the layers of molecules, applied to the faces of the primitive form, by which he supposed the secondary forms to be produced. [1913 Webster]

4.(Math.) The quantity by which a variable is diminished. [1913 Webster]

Equal decrement of life. (a) The decrease of life in a group of persons in which the assumed law of mortality is such that of a given large number of persons, all being now of the same age, an equal number shall die each consecutive year. (b) The decrease of life in a group of persons in which the assumed law of mortality is such that the ratio of those dying in a year to those living through the year is constant, being independent of the age of the persons. [1913 Webster]