these are nouns that show reference to a specifically identifiable object or set of objects. They also give their definiteness with determiners such as “the” and “my.” Ex. “My mother” and “Rachel”
Crystal, David. A Dictionary of Linguistics and Phonetics. The language library. Oxford, UK: Blackwell, 1997.
Matthews, P. H. The Concise Oxford Dictionary of Linguistics. Oxford: Oxford University Press, 1997.