Synonymy is the semantic relation of
sameness. When two words have the same
meanings, we say that they are
synonymous. While this is true, simply defining synonymy as sameness is rather unenlightening. Many
linguists prefer instead to define it as being "words whose similarities are greater than their differences". While this is a much looser definition, it serves to highlight the fact that it is the
differences in similar words that makes them interesting. How different can two words be and still be synonymous? Are there types of difference that break synonymy? Are there different kinds of synonymous pairings?
In general, we can break synonymy down into three categories, varying by degree.
- Absolute Synonymy
Two words are defined as being absolutely synonymous if they are are equinormal for all contexts. This means that for every context where Word A is perfectly acceptable, Word B is as well. Similarly, whenever Word A seems a bit strange or out of place, Word B must be equally out of place. In practice, almost no such pairs exist in normal language. Here are some examples that highlight the difficulty in finding words which are absolutely synonymous:
brave:courageous
Little Billy was so brave at the dentist's today.
Little Billy was so courageous at the dentist's today.
calm:placid
She was quite calm just a few minutes ago.
She was quite placid just a few minutes ago.
Inevitably it seems, we can find contexts where one of the words seems slightly inappropriate or slightly out of place, though JudyT points out that furze and gorse may be asbolutely synonymous.
In general, Absolute Synonymy is only really useful as a conceptual reference point.
- Propositional Synonymy
Two words are propositionally synonymous if they can be used in any truth functional expression and not change the value of the sentence.
Sally took the can from the box.
Sally took the tin from the box.
Alex plays the violin.
Alex plays the fiddle.
In a sentence like "Alex plays the fiddle in the orchestra" the use of 'fiddle' (a word which in this context typically is only used by professionals) preserves the truth value for the sentence and so is appropriate for propositional synonymy.
Differences in propositional synonymy typically are either of style, field of discourse, or in expressive meaning. In "the patient broke his shin" and "the patient broke his fibula", the difference comes from the field of discourse.
-
Near Synonymy
Essentially every synonymous word pairing that is neither of the two above. While the distinction between propositional synonymy and near synonymy is clear at least in theory, the line between near synonymy and non-synonymy is very difficult to draw formally. Fortunately, speakers seem to know intuitively whether terms are synonymous, even though we cannot formulate a specific definition.
See also: Meronymy, Hyponymy.
Information from:
Cruse, Alan, Meaning in Language: An Introduction to Semantics and Pragmatics, Oxford University Press, Oxford, 2000.
Thanks to JudyT for setting me straight about a few things!