We don't have synonyms for unites yet — it may be a rare, specialized, newly coined, or misspelled word. The closest thesaurus entries we have are unite, united and units.
(n) :
(UK, historical) A British gold coin worth 20 shillings, first produced during the reign of King James I, and bearing a legend indicating the king's intention of uniting the kingdoms of England and Scotland.
(n) :
(UK, historical) A British gold coin worth 20 shillings, first produced during the reign of King James I, and bearing a legend indicating the king's intention of uniting the kingdoms of England and Scotland.