Synonym

Two or more different terms which have identical or at least very similar meanings (extensions).

Examples of synonyms:

• House: home, building, residence, dynasty, parliament chamber …
• Horse: steed, stallion, mare, foal, current, sand bank, rock layer …
• Dog: hound, puppy, mongrel, bitch, clamp, person, villain, …

The term “synonym” is derived from the Greek synónymos [συνώνυμος], which is usually translated as “having the same name”. Specifically in this context, however, a translation such as “to be named the same” might be more fitting.

Synonyms are quasi the counterparts to equivocations: whereas the latter are terms that have several different extensions, these are different terms which denote identical or at least very similar things.

There are various subtypes of synonyms, depending on how exact they match in meaning. These range from the strictest form where there is an exact synonym (e.g. “cattle” = “cow”) to superordinate or subordinate terms (“horse” ⊃ “stallion”, “house” ⊂ “building”) which are only partially synonymous or only synonymous under certain circumstances.

A synonym can also only refer to specific meanings of the other term (e.g. “house” ⊂ “building” / “house” = “dynasty”). It follows that the synonyms of a term are not necessarily synonymous with each other (“building” ≠ “dynasty”).

Even if synonyms refer to the same extension in one way or another, they usually have different intensions, i.e. they convey different implications. For example, terms such as “mutt” or “hack” are synonyms of “dog” or “horse”, respectively, but carry specific pejorative connotations.

• Equivocation
• Extension
• Intension

• Synonym on Wikipedia