Full Idea
An expression ... should be reckoned a genuine singular term only if it resists elimination by paraphrase.
Gist of Idea
An expression is a genuine singular term if it resists elimination by paraphrase
Source
Bob Hale (Abstract Objects [1987], Ch.2.II)
Book Reference
Hale,Bob: 'Abstract Objects' [Blackwell 1987], p.24
A Reaction
This strikes me as extraordinarily optimistic. It will be relative to a language, and the resources of a given speaker, and seems open to the invention of new expressions to do the job (e.g. an equivalent adjective for every noun in the dictionary).
Related Idea
Idea 16375 Singular thoughts need a mental file, and an acquaintance relation from file to object [Recanati]