SYNONYMY
synonymy, synonymity, synonymousness
(noun) the semantic relation that holds between two words that can (in a given context) express the same meaning
Source: WordNet® 3.1
Etymology
Noun
synonymy (countable and uncountable, plural synonymies)
(semantics) The quality of being synonymous; sameness of meaning.
Antonym: antonymy
A list or collection of synonyms, often compared and contrasted.
The study of synonyms.
Synonym: synonymics
A system of synonyms.
(botany) The collective synonyms (all the names referring to a particular taxon, except the correct name)
(botany) The state of not being a correct name, of being a synonym
(zoology) The collective synonyms (all the names referring to the same taxon, including the correct name)
Source: Wiktionary
Syn*on"y*my, n. Etym: [L. synonymia, Gr. synonymie.]
1. The quality of being synonymous; sameness of meaning.
2. A system of synonyms.
3. (Rhet.)
Definition: A figure by which synonymous words are used to amplify a
discourse.
Source: Webster’s Unabridged Dictionary 1913 Edition