Here is a definition of paraphrase:
(1) A rewording of something written or spoken by someone else, esp. with the aim of making the sense clearer; a free rendering of a passage.
And here is a paraphrase of the definition of paraphrase:
(1a) A restatement of someone else’s writing or speech, particularly to clarify the meaning; an approximate version.
Can there be a definition, in turn, of paraphrase (1a)? No: a definition captures the general linguistic potential of a word or phrase, abstracted from any particular statement. A paraphrase reprises a particular statement, as (1a) reprises (1). For the same reason, there cannot be ...