The Collaborative International Dictionary of English v.0.48:
Cumulative \Cu"mu*la*tive\ (k?"m?-l?-t?v), a. [Cf. F.
1. Composed of parts in a heap; forming a mass; aggregated.
"As for knowledge which man receiveth by teaching, it is
cumulative, not original." --Bacon
2. Augmenting, gaining, or giving force, by successive
additions; as, a cumulative argument, i. e., one whose
force increases as the statement proceeds.
The argument . . . is in very truth not logical and
single, but moral and cumulative. --Trench.
(a) Tending to prove the same point to which other
evidence has been offered; -- said of evidence.
(b) Given by same testator to the same legatee; -- said of
a legacy. --Bouvier. --Wharton.
Cumulative action (Med.), that action of certain drugs, by
virtue of which they produce, when administered in small
doses repeated at considerable intervals, the same effect
as if given in a single large dose.
Cumulative poison, a poison the action of which is
Cumulative vote or Cumulative system of voting
(Politics), that system which allows to each voter as many
votes as there are persons to be voted for, and permits
him to accumulate these votes upon one person, or to
distribute them among the candidates as he pleases.