ABATEMENT n. 4 definitions
The act of abating, or the state of being abated; a lessening, diminution, or reduction; removal or putting an end to; as, the abatement of a nuisance is the suppression thereof.
ADDITION n.
Something added to a coat of arms, as a mark of honor; -- opposed to abatement. Vector addition (Geom.), that kind of addition of two lines, or vectors, AB and BC, by which their sum is regarded as the line, or vector, AC.