Definition:Aggregation


 * Algebra:
 * Aggregation: a collection of a number of terms into a parenthetical expression.


 * Set Theory:
 * Aggregation, or aggregate, is the word for set that was used since 's translation of up until the mid $20$th century, since which time set is all but universal.


 * Physics:
 * Aggregation: a discrete set of (usually) particles which are to be considered as under the same or well-definedly similar conditions at the introduction of an exposition.