noun
- a U.S. legal-tender note, printed in green on the back since the Civil War, originally issued against the credit of the country and not against gold or silver on deposit.
noun
- US informal an inconvertible legal-tender US currency note originally issued during the Civil War in 1862
- US slang a dollar bill
“U.S. dollar bill,” 1862, so called from the time of their introduction, from green (adj.) + back (n.); bank paper money printed in green ink had been called this since 1778 (as opposed to redbacks, etc.).