|Concept: term for an entity with certain properties. The properties of an object correspond to the features of the concept. These concept features are necessary in contrast to the properties of an individual object, which are always contingent.|
Books on Amazon
Def individual concept/Stalnaker: Function of poss. wrlds. on individuals. Thesis: As some singular terms are not rigid (E.g. "the baddest man in America"), as well as some predicates.
Ways a World may be Oxford New York 2003