yellow boy

== English == === Pronunciation === === Noun === yellow boy (countable and uncountable, plural yellow boys) (countable, slang, now archaic, historical) A gold coin; a guinea or sovereign. [from 17th c.] (uncountable, slang) Iron(III) hydroxide, a yellow-orange solid found in acidic water from mining projects. (countable, US, slang, historical) Synonym of goldback (“kind of gold certificate”).