From WordNet (r) 2.0 (August 2003) [wn]:
greenback
n : a piece of paper money (especially one issued by a central
bank); "he peeled off five one-thousand-zloty notes"
[syn: bill, note, government note, bank bill,
banker's bill, bank note, banknote, {Federal
Reserve note}]
From The Collaborative International Dictionary of English v.0.48 [gcide]:
Garfish \Gar"fish`\, n. [See Gar, n.] (Zool.)
(a) A European marine fish (Belone vulgaris); -- called
also gar, gerrick, greenback, greenbone,
gorebill, hornfish, longnose, mackerel guide,
sea needle, and sea pike.
(b) One of several species of similar fishes of the genus
Tylosurus, of which one species (T. marinus) is
common on the Atlantic coast. {T. Caribb[ae]us}, a very
large species, and T. crassus, are more southern; --
called also needlefish. Many of the common names of the
European garfish are also applied to the American
species.
[1913 Webster]
From The Collaborative International Dictionary of English v.0.48 [gcide]:
Greenback \Green"back"\, n.
One of the legal tender notes of the United States; a note of
paper currency of the United States; -- first issued in 1862,
and having the devices on the back printed with green ink, to
prevent alterations and counterfeits.
[1913 Webster]