1. presence in group: the addition of somebody or something to, or the presence of somebody or something in, a group or mixture
2. somebody or something included: somebody or something included in a group or mixture
3. geology substance inside mineral: a solid, liquid, or gas contained within a mineral or rock
4. cell biology foreign body in cell: a nonliving mass in the cytoplasm or nucleus of a cell, e.g. a starch grain or droplet of fat
5. mathematics relation between sets: in mathematics, the relation between two classes or sets when the second is a subset of the first
6. education teaching challenged children in regular classes: the practice of educating students with special needs in regular classes for all or nearly all of the day instead of in special education classes
[Early 17th century. < Latin inclus-, past participle of includere (see include)]
