Definition of "ducat"

Shylock: "My daughter! O my ducats! Fled with a Christian! O my Christian ducats! Justice! the law! my ducats, and my daughter!..."

c. 1596–1598 (date written), William Shakespeare, “The Merchant of Venice”, in Mr. William Shakespeares Comedies, Histories, & Tragedies […] (First Folio), London: […] Isaac Iaggard, and Ed[ward] Blount, published 1623, [Act II, scene viii]

But when the innkeeper saw what kind of goat the lad had, he thought this was a goat worth having, so when the lad had fallen asleep, he took another goat which couldn't make any golden ducats, and put that in its place.

1886, Peter Christen Asbjørnsen, translated by H.L. Brækstad, Folk and Fairy Tales, page 166

Ned Beaumont said, "Well, I've got a ducat that reads to there, anyway.

1972 , Dashiell Hammett, “IV. The Dog House”, in The Glass Key, Vintage Books, page 73

Customers are usually enticed in with a "ducat", or pass for one free dance.

1946, George Johnston, Skyscrapers in the Mist, page 88

[…] the lines at the box office since ducats went on sale publicly Wednesday […]

1949 June 11, Billboard