the act of including.

the state of being included.

something that is included.

Biology . a body suspended in the cytoplasm, as a granule.

Mineralogy . a solid body or a body of gas or liquid enclosed within the mass of a mineral.

Petrography . xenolith.

Logic, Mathematics . the relationship between two sets when the second is a subset of the first.

noun

exclusion , subtraction

noun

admittance , composition , comprisal , embodiment , embracement , encompassment , formation , incorporation , insertion , involvement , subsumption