Course paper english lexicology

1.2.3 Plesionymy (Near-Synonymy)

Near-synonyms bring forth or give sentences with different propositional content. They refer to lexical items that share some aspects of meaning and differ in others. Therefore, near-synonyms are expressions that are more or less similar, but not identical, in meaning. Cruse, Plesionyms are distinguished from cognitive synonyms by the fact that they yield sentences with different truth conditions: two sentences which differ only in respect of plesionyms in parallel syntactic positions are not mutually entailing, although if the lexical items are in hyponymous relation, there may well be unilateral entailment. There is always one member of a plesionymous pair, which is possible to assert, without paradox, while simultaneously denying the other member.

Unlike cognitive synonyms which have the same truth conditions, plesionyms have different truth conditions. Near-synonyms are different from cognitive synonyms by the fact that they give sentences with different propositional content. According to Farghal,⁸ the members of the synonymous pair foggy/ misty are near-synonyms rather than cognitive synonyms in that we can deny one while affirming the other. The sentence below illustrates this:
It wasn't foggy yesterday; it was just misty.
Clearly, mistiness is a lower degree of fogginess.
The difference between a plesionymous pair and a hyponymous one is that the lexical items in the former deny one another, as in: "He is not just fearless; but more exactly, he is brave", but in the latter (hyponymous pair) the lexical items involve inclusion and entailment, e.g., bus, car and truck are included in vehicle, and tulip and rose are included in flower. In fact, plesionyms differ from one another only in respect of "subordinate traits": subordinate traits are those which have a role within the meaning of a word analogous to that of a modifier in a syntactic construction, e.g., red in a red hat and quickly in ran quickly.