inclusion

noun

1. (countable)An addition or annex to a group, set, or total.

   “The poem was a new inclusion in the textbook.”

2. (uncountable)The act of including, i.e. adding or annexing, (something) to a group, set, or total.

   “The inclusion of the poem added value to the course.”

3. (countable)Anything foreign that is included in a material.
4. (countable)Any material that is trapped inside a mineral during its formation, as a defect in a precious stone.

   “The fewer inclusions a diamond has, the better is its clarity and value. Often the inclusions can be cut out of a diamond in the rough.”

5. (countable, uncountable)A nuclear or cytoplasmic aggregate of stainable substances.
6. (countable, uncountable)An object completely inside a tissue, such as epidermal inclusion cyst, a cyst in the epidermis.
7. (countable, uncountable)A mapping where the domain is a subset of the image.
8. (countable, obsolete, uncountable)Restriction; limitation.