The expression "the great seven" was used in the rioplatense trick ("card game with Spanish deck") when the card with the seven of swords was shown. Later (or earlier, as there is antecedents far from the Rio de la Plata) it began to be used as a euphemism for the exclamation "the great whore!" and from there 'seven' was mistaken for a harlot or a prostitute, but the meaning is different. See ahijuna .
