ə̇nˈklüzhən noun
( -s )
Etymology: Latin inclusion-, inclusio, from inclusus + -ion-, -io -ion
1. : the act of including or the state of being included
the inclusion of domestic … reforms in the social program of the government — H.C.Atyeo
2. : something that is included: as
a. : a gaseous, liquid, or solid and usually minute foreign body enclosed in the mass of a mineral
b. : a passive product of cell activity (as a starch grain) visible within the protoplasm
c. : solid and usually minute foreign particles (as of slag) enclosed in a solid metal
3. : a relation between two classes that obtains when all members of the first are also members of the second — contrasted with membership