ducat

American Heritage® Dictionary of the English Language, Fourth Edition

1. n. Any of various gold coins formerly used in certain European countries.
2. n. Slang A piece of money.
3. n. Slang An admission ticket.

Century Dictionary and Cyclopedia

1. n. A gold coin of varying form and value, formerly in use in several European countries. A ducat was first issued in Apulia, about the middle of the twelfth century, by the Norman duke Roger II. In 1283 a gold ducat was struck in Venice, but the piece was afterward called a zecchino (sequin), the ducat becoming only a money of account. (See def. 2.) The earliest gold coins of Germany seem to have been called ducats, and this name was applied to German gold coins of the sixteenth and seventeenth centuries. Gold coins called ducats were also issued in the Netherlands, in Hungary, and elsewhere. The value of the ducat varied but little, the coin usually containing from 3.42 to 3.44 grams of fine gold, worth from $2.27 to $2.32.
2. n. An old money of account in the Venetian republic.
3. n. plural Money; cash.
4. n. An Austrian weight for gold, which has been determined by Vienna authorities to be 3.490896 grams. This unit is supposed to have been derived through the Jews from the Ptolemaic drachma of 3.56 grams.

Wiktionary

1. n. historical A gold coin minted by various European nations.
2. n. Money in general.
3. n. A dollar (and, by extension, a eurodollar).

GNU Webster's 1913

1. n. A coin, either of gold or silver, of several countries in Europe; originally, one struck in the dominions of a duke.

WordNet 3.0

1. n. formerly a gold coin of various European countries