Definition - An ordered book of synonyms.
Note: This has become an archaic term. Since the mid-19th century, alphabetically ordered synonymies have, for the most part, been called Dictionaries (e.g. Longman's Synonym Dictionary ).

Example -
The British Synonymy (1794) by Hester Thrale Piozzi

Etymology -
The word derives via Latin from the Greek synonymon, word having the same sense as another (from syn, same + onyma, name)

Oxford English Dictionary -
Its first citation in this sense is from 1794:
"British Synonymy; or, an attempt at regulating the choice of words in familiar conversation."
(Mrs. Piozzi (title))

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