Attributive use

Attributive use is the use that a speaker makes of a definite noun phrase to say something about whatever fits the description of the noun phrase.

Example
The definite noun phrase in The murderer of Smith is insane is used attributively if the speaker does not intend to refer to a particular person which he knows to be the murderer of Smith (that would be the referential use), but to the (possibly unknown) person who murdered Smith, whoever that person may be.

Link
Utrecht Lexicon of Linguistics

Reference
Donnellan, K. 1966. Reference and definite descriptions. Philosophical Review 75: 281-304.