Merriam-Webster's Eleventh Collegiate Dictionary has this entry for the noun ducat:
ducat n {ME, fr. MF, fr. OIt ducato coin with the doge's portrait on it, fr. duca, doge, fr. LGk douk-, doux leader, fr. L -duc, dux} (14c) 1 : a former European usu. gold coin 2 : TICKET 2 ["a certificate or token showing that a fare or admission fee has been paid"]
I am wondering about the origin of the second meaning. How did ducats come to mean tickets for a show or performance?
Best Answer
Its current meaning as ticket probably derives from its prominent usage in Shakespeare's "The Merchant of Venice:"
Ducat:
(The Dictionary of American Slang)
Etymology:
(Etymonline)