from The American Heritage® Dictionary of the English Language, 4th Edition
- n. Informal Insignificant value: not worth a red cent.
from Wiktionary, Creative Commons Attribution/Share-Alike License
- n. A copper penny.
- n. A very small amount of money.
from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.
- n. something of little value
Probably from the color of the copper in which the coin was minted. (Wiktionary)