Sentence:  The late Proclamation for regulating the Gold Coin refers to the Reſolution or Order of the Lords of the Treaſury, dated July 24, 1773; [...] [T]he third Claſs in the above Table is ultimately to be the only ſtandard Gold <WSD>Coin of the Realm</WSD>. 
Meaning of the word marked with <WSD> tags:  The legal money of a country.