1. The act of aggregating; the state of being collected into a sum or mass; a collection of particulars; an aggregate.
2. In chimistry, the affinity of aggregation is the power which causes homogeneous bodies to tend towards each other, and to cohere; and from a mixture, which consists of parts dissimilar in their nature. The word is used of solid, fluid, or aeriform bodies.
3. The union and coherence of bodies of the same nature.