Call a tub a tub?

Medievalist.com has a list of phrases that originated in the Middle Ages, including this one:

To call a spade a spade

The ancient Greeks had popular proverb for plain speaking: “to call figs figs, and a tub a tub. However, when the scholar Erasmus created his Adagia, a collection of Greek and Latin proverbs, he mistook the Greek word spade for tub. In his version, it was written ‘to call a spade spade’ and it became popular ever since.