What is the meaning of Synonymy?

The quality of being synonymous; sameness of meaning.

A list or collection of synonyms, often compared and contrasted.

The use of synonyms to clarify or explain one's meaning.

The study of synonyms.

A system of synonyms.

The state of not being the name to be used, of being a synonym.

A group or list of synonyms.

Source: wiktionary.org