designatum

Designatum is a term used in philosophy of language and semantics to denote the object or class of objects that a linguistic expression designates. It is the referent or extension of a term, distinct from the sign or the sense of the term. The concept helps distinguish what a term means from what it points to in the world.

For proper names, the designatum is typically a single object in reality, the entity the name picks out. For general terms and predicates, the designatum is the extension—the set of all objects that satisfy the term or description. For example, the designatum of the name "Earth" is the planet Earth; the designatum of the predicate "dog" is the class of all dogs.

In discussions of designation, designata are often contrasted with designators (the linguistic expression itself) and with sense or meaning. The same designatum can be associated with different senses or descriptions, as in the case of "the Morning Star" and "the Evening Star," which designate Venus despite differing expressions.

Designatum also interacts with broader notions such as reference, extension, and truth conditions. In some theories, the designatum is context-dependent or varies across possible worlds; in others, it is taken as fixed by the world or model under discussion. Although the term designatum is less common in contemporary mainstream semantics, it remains a useful label in historical and analytical discussions of designation and reference.