Since a word is a symbol for a concept, it has no meaning apart from the content of the concept it symbolizes. And since a concept is an integration of units, it has no content or meaning apart from its units. The meaning of a concept consists of the units — the existents — which it integrates, including all the characteristics of these units.
Observe that concepts mean existents, not arbitrarily selected portions of existents....
Metaphysically, an entity is: all of the things which it is. Each of its characteristics has the same metaphysical status: each constitutes a part of the entity's identity.
Epistemologically, all the characteristics of the entities subsumed under a concept are discovered by the same basic method: by observation of these entities. The initial similarities, on the basis of which certain concretes were isolated and conceptually integrated, were grasped by a process of observation; all subsequently discovered characteristics of these concretes are discovered by the same method (no matter how complex the inductive processes involved may become).
The fact that certain characteristics are, at a given time, unknown to man, does not indicate that these characteristics are excluded from the entity — or from the concept. A is A; existents are what they are, independent of the state of human knowledge; and a concept means the existents which it integrates. Thus, a concept subsumes and includes all the characteristics of its referents, known and not-yet-known. [IOTE, 98-99]
Rand's strange doctrine that "a concept means the existents which it integrates" leads her to adopt a quasi-Platonist view of concepts. Concepts are not seen as psychological processes occurring within an actual human brain, but as ideal forms which real concepts can approach, if never quite match. Peikoff complains about the Platonic "essence-accident" dichotomy, which he suggests is at the root of the ASD. But there is a dichotomy in Rand that is far more perplexing and gratuitous: the dichotomy between concepts as immaculate representations subsuming all the characteristics of a referent, and the actual concepts human beings hold within their minds. Apologists for Rand will undoubtedly cry foul over my description of the Objectivist theory. But I have merely drawn out what is clearly implied by the theory itself. "A concept subsumes and includes all the characteristics of its referents, known and not-yet-known," declares Peikoff (undoubtedly speaking for Rand). How can a concept existing in a human mind include not-yet-known information? The only way this theory makes any sense is to assume that a concept is a kind of ideal construct, which our minds are trying to approach. Actual concepts (i.e., concepts existing in human minds) must fall short of that ideal construct, because human beings, as even Rand admits, are fallible. On this view of concepts, the aim of knowledge would be to approach that ideal concept as much as is humanly possible.

